diff --git a/samples/cxx/bvp/BoundaryValueProblem.h b/samples/cxx/bvp/BoundaryValueProblem.h
index b9b7b4fce..d67ad4680 100644
--- a/samples/cxx/bvp/BoundaryValueProblem.h
+++ b/samples/cxx/bvp/BoundaryValueProblem.h
@@ -155,7 +155,7 @@ public:
      */
     void writeCSV(std::string filename = "output.csv",
                   bool dotitles = true, std::string ztitle = "z") const {
-        std::ofstream f(filename.c_str());
+        std::ofstream f(filename);
         int np = nPoints();
         int nc = nComponents();
         int n, m;
diff --git a/src/base/application.cpp b/src/base/application.cpp
index 18d17ca39..0c80c1a94 100644
--- a/src/base/application.cpp
+++ b/src/base/application.cpp
@@ -503,7 +503,7 @@ std::string Application::findInputFile(const std::string& name)
         inname = "";
         for (size_t i = 0; i < nd; i++) {
             inname = dirs[i] + "/" + name;
-            std::ifstream fin(inname.c_str());
+            std::ifstream fin(inname);
             if (fin) {
                 fin.close();
                 return inname;
diff --git a/src/base/ct2ctml.cpp b/src/base/ct2ctml.cpp
index 99220822f..aac470034 100644
--- a/src/base/ct2ctml.cpp
+++ b/src/base/ct2ctml.cpp
@@ -72,7 +72,7 @@ void ct2ctml(const char* file, const int debug)
     } else {
         out_name += ".xml";
     }
-    std::ofstream out(out_name.c_str());
+    std::ofstream out(out_name);
     out << xml;
 }
 
diff --git a/src/base/plots.cpp b/src/base/plots.cpp
index bf17c7955..eb6162039 100644
--- a/src/base/plots.cpp
+++ b/src/base/plots.cpp
@@ -15,7 +15,7 @@ void writePlotFile(const std::string& fname, const std::string& fmt,
                    const std::vector<std::string> &names,
                    const Array2D& data)
 {
-    ofstream f(fname.c_str());
+    ofstream f(fname);
     if (!f) {
         throw CanteraError("writePlotFile","could not open file "+fname+
                            " for writing.");
diff --git a/src/clib/ctxml.cpp b/src/clib/ctxml.cpp
index d00e166c0..132759c11 100644
--- a/src/clib/ctxml.cpp
+++ b/src/clib/ctxml.cpp
@@ -89,7 +89,7 @@ extern "C" {
         try {
             writelog("WARNING: xml_build called. Use get_XML_File instead.");
             string path = findInputFile(file);
-            ifstream f(path.c_str());
+            ifstream f(path);
             if (!f) {
                 throw CanteraError("xml_build",
                                    "file "+string(file)+" not found.");
diff --git a/src/equil/BasisOptimize.cpp b/src/equil/BasisOptimize.cpp
index fdf5ccf1c..777bd30ec 100644
--- a/src/equil/BasisOptimize.cpp
+++ b/src/equil/BasisOptimize.cpp
@@ -241,11 +241,10 @@ size_t BasisOptimize(int* usedZeroedSpecies, bool doFormRxn, MultiPhase* mphase,
         if (jr != k) {
             if (DEBUG_MODE_ENABLED && BasisOptimize_print_lvl >= 1) {
                 kk = orderVectorSpecies[k];
-                sname = mphase->speciesName(kk);
-                writelogf("   ---   %-12.12s", sname.c_str());
+                writelogf("   ---   %-12.12s", mphase->speciesName(kk));
                 jj = orderVectorSpecies[jr];
-                ename = mphase->speciesName(jj);
-                writelogf("(%9.2g) replaces %-12.12s", molSave, ename.c_str());
+                writelogf("(%9.2g) replaces %-12.12s",
+                          molSave, mphase->speciesName(jj));
                 writelogf("(%9.2g) as component %3d\n", molNum[jj], jr);
             }
             std::swap(orderVectorSpecies[jr], orderVectorSpecies[k]);
@@ -336,8 +335,7 @@ size_t BasisOptimize(int* usedZeroedSpecies, bool doFormRxn, MultiPhase* mphase,
         writelog("\n   ---        NonComponent |   Moles  |       ");
         for (i = 0; i < nComponents; i++) {
             kk = orderVectorSpecies[i];
-            sname = mphase->speciesName(kk);
-            writelogf("%-11.10s", sname.c_str());
+            writelogf("%-11.10s", mphase->speciesName(kk));
         }
         writelog("\n");
 
@@ -345,8 +343,7 @@ size_t BasisOptimize(int* usedZeroedSpecies, bool doFormRxn, MultiPhase* mphase,
             k = i + nComponents;
             kk = orderVectorSpecies[k];
             writelogf("   --- %3d (%3d) ", k, kk);
-            sname = mphase->speciesName(kk);
-            writelogf("%-10.10s", sname.c_str());
+            writelogf("%-10.10s", mphase->speciesName(kk));
             writelogf("|%10.3g|", molNumBase[kk]);
             /*
              * Print the negative of formRxnMatrix[]; it's easier to interpret.
@@ -596,13 +593,11 @@ void ElemRearrange(size_t nComponents, const vector_fp& elementAbundances,
         if (jr != k) {
             if (DEBUG_MODE_ENABLED && BasisOptimize_print_lvl > 0) {
                 kk = orderVectorElements[k];
-                ename = mphase->elementName(kk);
                 writelog("   ---   ");
-                writelogf("%-2.2s", ename.c_str());
+                writelogf("%-2.2s", mphase->elementName(kk));
                 writelog("replaces ");
                 kk = orderVectorElements[jr];
-                ename = mphase->elementName(kk);
-                writelogf("%-2.2s", ename.c_str());
+                writelogf("%-2.2s", mphase->elementName(kk));
                 writelogf(" as element %3d\n", jr);
             }
             std::swap(orderVectorElements[jr], orderVectorElements[k]);
diff --git a/src/equil/ChemEquil.cpp b/src/equil/ChemEquil.cpp
index 7e4725791..207610ff5 100644
--- a/src/equil/ChemEquil.cpp
+++ b/src/equil/ChemEquil.cpp
@@ -216,15 +216,13 @@ int ChemEquil::setInitialMoles(thermo_t& s, vector_fp& elMoleGoal,
             writelogf("  Temperature = %g\n", s.temperature());
             writelogf("  Pressure = %g\n", s.pressure());
             for (size_t k = 0; k < m_kk; k++) {
-                string nnn = s.speciesName(k);
-                double mf = s.moleFraction(k);
-                writelogf("         %-12s % -10.5g\n", nnn.c_str(), mf);
+                writelogf("         %-12s % -10.5g\n",
+                          s.speciesName(k), s.moleFraction(k));
             }
             writelog("      Element_Name   ElementGoal  ElementMF\n");
             for (size_t m = 0; m < m_mm; m++) {
-                string nnn = s.elementName(m);
                 writelogf("      %-12s % -10.5g% -10.5g\n",
-                          nnn.c_str(), elMoleGoal[m], m_elementmolefracs[m]);
+                          s.elementName(m), elMoleGoal[m], m_elementmolefracs[m]);
             }
         }
 
@@ -276,9 +274,8 @@ int ChemEquil::estimateElementPotentials(thermo_t& s, vector_fp& lambda_RT,
 
     if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0) {
         for (size_t m = 0; m < m_nComponents; m++) {
-            int isp = static_cast<int>(m_component[m]);
-            string nnn = s.speciesName(isp);
-            writelogf("isp = %d, %s\n", isp, nnn.c_str());
+            size_t isp = m_component[m];
+            writelogf("isp = %d, %s\n", isp, s.speciesName(isp));
         }
         double pres = s.pressure();
         double temp = s.temperature();
@@ -286,9 +283,8 @@ int ChemEquil::estimateElementPotentials(thermo_t& s, vector_fp& lambda_RT,
         writelogf("Temperature = %g\n", temp);
         writelog("  id       Name     MF     mu/RT \n");
         for (size_t n = 0; n < s.nSpecies(); n++) {
-            string nnn = s.speciesName(n);
             writelogf("%10d %15s %10.5g %10.5g\n",
-                      n, nnn.c_str(), xMF_est[n], mu_RT[n]);
+                      n, s.speciesName(n), xMF_est[n], mu_RT[n]);
         }
     }
     DenseMatrix aa(m_nComponents, m_nComponents, 0.0);
@@ -315,18 +311,16 @@ int ChemEquil::estimateElementPotentials(thermo_t& s, vector_fp& lambda_RT,
         for (size_t m = 0; m < m_nComponents; m++) {
             size_t isp = m_component[m];
             double tmp = 0.0;
-            string sname = s.speciesName(isp);
             for (size_t n = 0; n < m_mm; n++) {
                 tmp += nAtoms(isp, n) * lambda_RT[n];
             }
             writelogf("%3d %16s  %10.5g   %10.5g   %10.5g\n",
-                      m, sname.c_str(), mu_RT[isp], tmp, tmp - mu_RT[isp]);
+                      m, s.speciesName(isp), mu_RT[isp], tmp, tmp - mu_RT[isp]);
         }
 
         writelog(" id    ElName  Lambda_RT\n");
         for (size_t m = 0; m < m_mm; m++) {
-            string ename = s.elementName(m);
-            writelogf(" %3d  %6s  %10.5g\n", m, ename.c_str(), lambda_RT[m]);
+            writelogf(" %3d  %6s  %10.5g\n", m, s.elementName(m), lambda_RT[m]);
         }
     }
     return info;
@@ -1037,16 +1031,15 @@ int ChemEquil::estimateEP_Brinkley(thermo_t& s, vector_fp& x,
         writelog("Initial mole numbers and mu_SS:\n");
         writelog("         Name           MoleNum        mu_SS   actCoeff\n");
         for (k = 0; k < m_kk; k++) {
-            string nnn = s.speciesName(k);
             writelogf("%15s  %13.5g  %13.5g %13.5g\n",
-                      nnn.c_str(), n_i[k], m_muSS_RT[k], actCoeff[k]);
+                      s.speciesName(k), n_i[k], m_muSS_RT[k], actCoeff[k]);
         }
         writelogf("Initial n_t = %10.5g\n", n_t);
         writelog("Comparison of Goal Element Abundance with Initial Guess:\n");
         writelog("  eName       eCurrent       eGoal\n");
         for (m = 0; m < m_mm; m++) {
-            string nnn = s.elementName(m);
-            writelogf("%5s   %13.5g  %13.5g\n",nnn.c_str(), eMolesFix[m], elMoles[m]);
+            writelogf("%5s   %13.5g  %13.5g\n",
+                      s.elementName(m), eMolesFix[m], elMoles[m]);
         }
     }
     for (m = 0; m < m_mm; m++) {
@@ -1086,14 +1079,14 @@ int ChemEquil::estimateEP_Brinkley(thermo_t& s, vector_fp& x,
         if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0) {
             writelog("        Species: Calculated_Moles Calculated_Mole_Fraction\n");
             for (k = 0; k < m_kk; k++) {
-                string nnn = s.speciesName(k);
-                writelogf("%15s: %10.5g %10.5g\n", nnn.c_str(), n_i_calc[k], Xmol_i_calc[k]);
+                writelogf("%15s: %10.5g %10.5g\n",
+                          s.speciesName(k), n_i_calc[k], Xmol_i_calc[k]);
             }
             writelogf("%15s: %10.5g\n", "Total Molar Sum", n_t_calc);
             writelogf("(iter %d) element moles bal:   Goal  Calculated\n", iter);
             for (m = 0; m < m_mm; m++) {
-                string nnn = s.elementName(m);
-                writelogf("              %8s: %10.5g %10.5g \n", nnn.c_str(), elMoles[m], eMolesCalc[m]);
+                writelogf("              %8s: %10.5g %10.5g \n",
+                          s.elementName(m), elMoles[m], eMolesCalc[m]);
             }
         }
 
@@ -1197,8 +1190,8 @@ int ChemEquil::estimateEP_Brinkley(thermo_t& s, vector_fp& x,
                     }
                 }
                 if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0) {
-                    string nnn = s.elementName(m);
-                    writelogf("               %5s %3d : %5d  %5d\n",nnn.c_str(), lumpSum[m], kMSp, kMSp2);
+                    writelogf("               %5s %3d : %5d  %5d\n",
+                              s.elementName(m), lumpSum[m], kMSp, kMSp2);
                 }
             }
 
@@ -1443,8 +1436,8 @@ int ChemEquil::estimateEP_Brinkley(thermo_t& s, vector_fp& x,
         if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0) {
             writelogf("(it %d)    OLD_SOLUTION  NEW SOLUTION    (undamped updated)\n", iter);
             for (m = 0; m < m_mm; m++) {
-                string eee = s.elementName(m);
-                writelogf("     %5s   %10.5g   %10.5g   %10.5g\n", eee.c_str(), x_old[m], x[m], resid[m]);
+                writelogf("     %5s   %10.5g   %10.5g   %10.5g\n",
+                          s.elementName(m), x_old[m], x[m], resid[m]);
             }
             writelogf("       n_t    %10.5g   %10.5g  %10.5g \n", x_old[m_mm], n_t, exp(resid[m_mm]));
         }
@@ -1510,9 +1503,8 @@ void ChemEquil::adjustEloc(thermo_t& s, vector_fp& elMolesGoal)
         }
         double factor = (elMolesGoal[m_eloc] + sumNeg) / sumPos;
         if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0 && factor < 0.9999999999) {
-            string nnn = s.speciesName(maxPosEloc);
             writelogf("adjustEloc: adjusted %s and friends from %g to %g to ensure neutrality condition\n",
-                      nnn.c_str(),
+                      s.speciesName(maxPosEloc),
                       m_molefractions[maxPosEloc], m_molefractions[maxPosEloc]*factor);
         }
         for (k = 0; k < m_kk; k++) {
@@ -1523,9 +1515,8 @@ void ChemEquil::adjustEloc(thermo_t& s, vector_fp& elMolesGoal)
     } else {
         double factor = (-elMolesGoal[m_eloc] + sumPos) / sumNeg;
         if (DEBUG_MODE_ENABLED && ChemEquil_print_lvl > 0 && factor < 0.9999999999) {
-            string nnn = s.speciesName(maxNegEloc);
             writelogf("adjustEloc: adjusted %s and friends from %g to %g to ensure neutrality condition\n",
-                      nnn.c_str(),
+                      s.speciesName(maxNegEloc),
                       m_molefractions[maxNegEloc], m_molefractions[maxNegEloc]*factor);
         }
         for (k = 0; k < m_kk; k++) {
diff --git a/src/equil/vcs_MultiPhaseEquil.cpp b/src/equil/vcs_MultiPhaseEquil.cpp
index c1db55003..107b2562d 100644
--- a/src/equil/vcs_MultiPhaseEquil.cpp
+++ b/src/equil/vcs_MultiPhaseEquil.cpp
@@ -550,7 +550,7 @@ int vcs_MultiPhaseEquil::equilibrate_TP(int estimateEquil,
         plogf("--------------------------------------------------"
               "-----------\n");
         for (size_t i = 0; i < m_vprob.nspecies; i++) {
-            plogf("%-12s", m_vprob.SpName[i].c_str());
+            plogf("%-12s", m_vprob.SpName[i]);
             if (m_vprob.SpeciesUnknownType[i] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("  %15.3e %15.3e  ", 0.0, m_vprob.mf[i]);
                 plogf("%15.3e\n", m_vprob.m_gibbsSpecies[i]);
@@ -1343,7 +1343,7 @@ int vcs_MultiPhaseEquil::determine_PhaseStability(int iph, double& funcStab, int
         }
         plogf("-------------------------------------------------------------\n");
         for (size_t i = 0; i < m_vprob.nspecies; i++) {
-            plogf("%-12s", m_vprob.SpName[i].c_str());
+            plogf("%-12s", m_vprob.SpName[i]);
             if (m_vprob.SpeciesUnknownType[i] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("  %15.3e %15.3e  ", 0.0, m_vprob.mf[i]);
                 plogf("%15.3e\n", m_vprob.m_gibbsSpecies[i]);
diff --git a/src/equil/vcs_elem.cpp b/src/equil/vcs_elem.cpp
index f81cb7ba9..9d5aed58d 100644
--- a/src/equil/vcs_elem.cpp
+++ b/src/equil/vcs_elem.cpp
@@ -204,8 +204,8 @@ int VCS_SOLVE::vcs_elcorr(double aa[], double x[])
                             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 3) {
                                 plogf("  ---  vcs_elcorr: Reduced species %s from %g to %g "
                                       "due to %s max bounds constraint\n",
-                                      m_speciesName[kspec].c_str(), m_molNumSpecies_old[kspec],
-                                      maxPermissible, m_elementName[i].c_str());
+                                      m_speciesName[kspec], m_molNumSpecies_old[kspec],
+                                      maxPermissible, m_elementName[i]);
                             }
                             m_molNumSpecies_old[kspec] = maxPermissible;
                             changed = true;
@@ -219,7 +219,7 @@ int VCS_SOLVE::vcs_elcorr(double aa[], double x[])
                                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                                     plogf("  ---  vcs_elcorr: Zeroed species %s and changed "
                                           "status to %d due to max bounds constraint\n",
-                                          m_speciesName[kspec].c_str(), m_speciesStatus[kspec]);
+                                          m_speciesName[kspec], m_speciesStatus[kspec]);
                                 }
                             }
                         }
@@ -460,7 +460,7 @@ L_CLEANUP:
               "              Final\n");
         for (size_t i = 0; i < m_numElemConstraints; ++i) {
             plogf("   ---       ");
-            plogf("%-2.2s", m_elementName[i].c_str());
+            plogf("%-2.2s", m_elementName[i]);
             plogf(" %20.12E %20.12E %20.12E\n", m_elemAbundancesGoal[i], ga_save[i], m_elemAbundances[i]);
         }
         plogf("   ---            Diff_Norm:         %20.12E %20.12E\n",
diff --git a/src/equil/vcs_elem_rearrange.cpp b/src/equil/vcs_elem_rearrange.cpp
index ade50444b..d7760bdb9 100644
--- a/src/equil/vcs_elem_rearrange.cpp
+++ b/src/equil/vcs_elem_rearrange.cpp
@@ -147,9 +147,9 @@ int VCS_SOLVE::vcs_elem_rearrange(double* const aw, double* const sa,
         if (jr != k) {
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                 plogf("   ---   ");
-                plogf("%-2.2s", m_elementName[k].c_str());
+                plogf("%-2.2s", m_elementName[k]);
                 plogf("(%9.2g) replaces ", m_elemAbundancesGoal[k]);
-                plogf("%-2.2s", m_elementName[jr].c_str());
+                plogf("%-2.2s", m_elementName[jr]);
                 plogf("(%9.2g) as element %3d", m_elemAbundancesGoal[jr], jr);
                 plogendl();
             }
diff --git a/src/equil/vcs_inest.cpp b/src/equil/vcs_inest.cpp
index e71152519..908b0138b 100644
--- a/src/equil/vcs_inest.cpp
+++ b/src/equil/vcs_inest.cpp
@@ -38,7 +38,7 @@ void VCS_SOLVE::vcs_inest(double* const aw, double* const sa, double* const sm,
         plogf("%s     SPECIES          MOLE_NUMBER      -SS_ChemPotential\n", pprefix);
         for (size_t kspec = 0; kspec < nspecies; ++kspec) {
             plogf("%s     ", pprefix);
-            plogf("%-12.12s", m_speciesName[kspec].c_str());
+            plogf("%-12.12s", m_speciesName[kspec]);
             plogf(" %15.5g  %12.3g\n", m_molNumSpecies_old[kspec], -m_SSfeSpecies[kspec]);
         }
         plogf("%s Element Abundance Agreement returned from linear "
@@ -53,7 +53,7 @@ void VCS_SOLVE::vcs_inest(double* const aw, double* const sa, double* const sm,
                     tmp += m_formulaMatrix(kspec,j) * m_molNumSpecies_old[kspec];
                 }
                 plogf("%s     ", pprefix);
-                plogf("   %-9.9s", m_elementName[j].c_str());
+                plogf("   %-9.9s", m_elementName[j]);
                 plogf(" %12.3g %12.3g\n", m_elemAbundancesGoal[j], tmp);
             }
         }
@@ -134,7 +134,7 @@ void VCS_SOLVE::vcs_inest(double* const aw, double* const sa, double* const sm,
     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
         for (size_t kspec = 0; kspec < nspecies; ++kspec) {
             plogf("%s", pprefix);
-            plogf("%-12.12s", m_speciesName[kspec].c_str());
+            plogf("%-12.12s", m_speciesName[kspec]);
             if (kspec < m_numComponents) {
                 plogf("fe* = %15.5g ff = %15.5g\n", m_feSpecies_new[kspec],
                       m_SSfeSpecies[kspec]);
@@ -195,7 +195,7 @@ void VCS_SOLVE::vcs_inest(double* const aw, double* const sa, double* const sm,
         for (size_t kspec = 0; kspec < nspecies; ++kspec) {
             if (m_speciesUnknownType[kspec] != VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("%sdirection (", pprefix);
-                plogf("%-12.12s", m_speciesName[kspec].c_str());
+                plogf("%-12.12s", m_speciesName[kspec]);
                 plogf(") = %g", m_deltaMolNumSpecies[kspec]);
                 if (m_SSPhase[kspec]) {
                     if (m_molNumSpecies_old[kspec] > 0.0) {
@@ -307,7 +307,7 @@ void VCS_SOLVE::vcs_inest(double* const aw, double* const sa, double* const sm,
         plogf("%s     SPECIES      MOLE_NUMBER\n", pprefix);
         for (size_t kspec = 0; kspec < nspecies; ++kspec) {
             plogf("%s     ", pprefix);
-            plogf("%-12.12s", m_speciesName[kspec].c_str());
+            plogf("%-12.12s", m_speciesName[kspec]);
             plogf(" %g", m_molNumSpecies_old[kspec]);
             plogendl();
         }
diff --git a/src/equil/vcs_phaseStability.cpp b/src/equil/vcs_phaseStability.cpp
index 05c492d00..af20604d2 100644
--- a/src/equil/vcs_phaseStability.cpp
+++ b/src/equil/vcs_phaseStability.cpp
@@ -229,9 +229,7 @@ size_t VCS_SOLVE::vcs_popPhaseID(std::vector<size_t> & phasePopPhaseIDs)
         if (existence > 0) {
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                 plogf("  ---    %18s %5d           NA       %11.3e\n",
-                      Vphase->PhaseName.c_str(),
-                      existence,
-                      m_tPhaseMoles_old[iph]);
+                      Vphase->PhaseName, existence, m_tPhaseMoles_old[iph]);
             }
         } else {
             if (Vphase->m_singleSpecies) {
@@ -262,8 +260,7 @@ size_t VCS_SOLVE::vcs_popPhaseID(std::vector<size_t> & phasePopPhaseIDs)
 
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                     plogf("  ---    %18s %5d %10.3g %10.3g %s\n",
-                          Vphase->PhaseName.c_str(),
-                          existence, Fephase,
+                          Vphase->PhaseName, existence, Fephase,
                           m_tPhaseMoles_old[iph], anote);
                 }
             } else {
@@ -282,14 +279,13 @@ size_t VCS_SOLVE::vcs_popPhaseID(std::vector<size_t> & phasePopPhaseIDs)
                     }
                     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                         plogf("  ---    %18s %5d  %11.3g %11.3g\n",
-                              Vphase->PhaseName.c_str(),
-                              existence, Fephase,
+                              Vphase->PhaseName, existence, Fephase,
                               m_tPhaseMoles_old[iph]);
                     }
                 } else {
                     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                         plogf("  ---    %18s %5d   blocked  %11.3g\n",
-                              Vphase->PhaseName.c_str(),
+                              Vphase->PhaseName,
                               existence, m_tPhaseMoles_old[iph]);
                     }
                 }
@@ -329,7 +325,7 @@ int VCS_SOLVE::vcs_popPhaseRxnStepSizes(const size_t iphasePop)
                    "called for a phase that exists!");
     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
         plogf("  ---  vcs_popPhaseRxnStepSizes() called to pop phase %s %d into existence\n",
-              Vphase->PhaseName.c_str(), iphasePop);
+              Vphase->PhaseName, iphasePop);
     }
     // Section for a single-species phase
     if (Vphase->m_singleSpecies) {
diff --git a/src/equil/vcs_prob.cpp b/src/equil/vcs_prob.cpp
index d0ee5555a..60bca1799 100644
--- a/src/equil/vcs_prob.cpp
+++ b/src/equil/vcs_prob.cpp
@@ -187,8 +187,8 @@ void VCS_PROB::prob_report(int print_lvl)
         plogf(" Initial_Estimated_Moles   Species_Type\n");
         for (size_t i = 0; i < nspecies; i++) {
             vcs_VolPhase* Vphase = VPhaseList[PhaseID[i]];
-            plogf("%16s      %5d   %16s", SpName[i].c_str(), PhaseID[i],
-                  Vphase->PhaseName.c_str());
+            plogf("%16s      %5d   %16s", SpName[i], PhaseID[i],
+                  Vphase->PhaseName);
             if (iest >= 0) {
                 plogf("             %-10.5g", w[i]);
             } else {
@@ -216,9 +216,9 @@ void VCS_PROB::prob_report(int print_lvl)
         for (size_t iphase = 0; iphase < NPhase; iphase++) {
             vcs_VolPhase* Vphase = VPhaseList[iphase];
             std::string EOS_cstr = string16_EOSType(Vphase->m_eqnState);
-            plogf("%16s %5d %5d %8d ", Vphase->PhaseName.c_str(),
+            plogf("%16s %5d %5d %8d ", Vphase->PhaseName,
                   Vphase->VP_ID_, Vphase->m_singleSpecies, Vphase->m_gasPhase);
-            plogf("%16s %8d %16e ", EOS_cstr.c_str(),
+            plogf("%16s %8d %16e ", EOS_cstr,
                   Vphase->nSpecies(), Vphase->totalMolesInert());
             if (iest >= 0) {
                 plogf("%16e\n", Vphase->totalMoles());
@@ -235,7 +235,7 @@ void VCS_PROB::prob_report(int print_lvl)
         }
         for (size_t i = 0; i < ne; ++i) {
             writeline(' ', 26, false);
-            plogf("%-2.2s", ElName[i].c_str());
+            plogf("%-2.2s", ElName[i]);
             plogf("%20.12E  ", fac * gai[i]);
             plogf("%3d       %3d\n", m_elType[i], ElActive[i]);
         }
@@ -260,9 +260,9 @@ void VCS_PROB::prob_report(int print_lvl)
             Vphase->setState_TP(T, PresPA);
             for (size_t kindex = 0; kindex < Vphase->nSpecies(); kindex++) {
                 size_t kglob = Vphase->spGlobalIndexVCS(kindex);
-                plogf("%16s ", SpName[kglob].c_str());
+                plogf("%16s ", SpName[kglob]);
                 if (kindex == 0) {
-                    plogf("%16s", Vphase->PhaseName.c_str());
+                    plogf("%16s", Vphase->PhaseName);
                 } else {
                     plogf("                ");
                 }
diff --git a/src/equil/vcs_report.cpp b/src/equil/vcs_report.cpp
index 2d1e8c78b..0e0d376c3 100644
--- a/src/equil/vcs_report.cpp
+++ b/src/equil/vcs_report.cpp
@@ -94,7 +94,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     plogf("Mole Fraction    ChemPot/RT    SpecUnkType\n");
     writeline('-', 80);
     for (size_t i = 0; i < m_numComponents; ++i) {
-        plogf(" %-12.12s", m_speciesName[i].c_str());
+        plogf(" %-12.12s", m_speciesName[i]);
         writeline(' ', 13, false);
         plogf("%14.7E     %14.7E    %12.4E", m_molNumSpecies_old[i] * molScale,
               m_molNumSpecies_new[i] * molScale, m_feSpecies_old[i]);
@@ -103,7 +103,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     }
     for (size_t i = m_numComponents; i < m_numSpeciesRdc; ++i) {
         size_t l = sortindex[i];
-        plogf(" %-12.12s", m_speciesName[l].c_str());
+        plogf(" %-12.12s", m_speciesName[l]);
         writeline(' ', 13, false);
 
         if (m_speciesUnknownType[l] == VCS_SPECIES_TYPE_MOLNUM) {
@@ -125,7 +125,7 @@ int VCS_SOLVE::vcs_report(int iconv)
                 plogf(" Inert Gas Species        ");
             } else {
                 plogf(" Inert Species in phase %16s ",
-                      m_VolPhaseList[i]->PhaseName.c_str());
+                      m_VolPhaseList[i]->PhaseName);
             }
             plogf("%14.7E     %14.7E    %12.4E\n", TPhInertMoles[i] * molScale,
                   TPhInertMoles[i] / m_tPhaseMoles_old[i], 0.0);
@@ -134,7 +134,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     if (m_numSpeciesRdc != nspecies) {
         plogf("\n SPECIES WITH LESS THAN 1.0E-32 KMOLES:\n\n");
         for (size_t kspec = m_numSpeciesRdc; kspec < nspecies; ++kspec) {
-            plogf(" %-12.12s", m_speciesName[kspec].c_str());
+            plogf(" %-12.12s", m_speciesName[kspec]);
             // Note m_deltaGRxn_new[] stores in kspec slot not irxn slot, after solve
             plogf("             %14.7E     %14.7E    %12.4E",
                   m_molNumSpecies_old[kspec]*molScale,
@@ -163,7 +163,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     plogf(" |           |\n");
     plogf("               | Components|");
     for (size_t j = 0; j < m_numComponents; j++) {
-        plogf(" %10.10s", m_speciesName[j].c_str());
+        plogf(" %10.10s", m_speciesName[j]);
     }
     plogf(" |           |\n");
     plogf(" NonComponent  |   Moles   |");
@@ -175,7 +175,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     for (size_t irxn = 0; irxn < m_numRxnTot; irxn++) {
         size_t kspec = m_indexRxnToSpecies[irxn];
         plogf(" %3d ", kspec);
-        plogf("%-10.10s", m_speciesName[kspec].c_str());
+        plogf("%-10.10s", m_speciesName[kspec]);
         plogf("|%10.3g |", m_molNumSpecies_old[kspec]*molScale);
         for (size_t j = 0; j < m_numComponents; j++) {
             plogf("     %6.2f", m_stoichCoeffRxnMatrix(j,irxn));
@@ -204,7 +204,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     plogf(" |                     |\n");
     plogf("                  | Element   |");
     for (size_t j = 0; j < m_numElemConstraints; j++) {
-        plogf(" %10.10s", m_elementName[j].c_str());
+        plogf(" %10.10s", m_elementName[j]);
     }
     plogf(" |                     |\n");
     plogf("    PhaseName     |KMolTarget |");
@@ -216,7 +216,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     for (size_t iphase = 0; iphase < m_numPhases; iphase++) {
         plogf(" %3d ", iphase);
         vcs_VolPhase* VPhase = m_VolPhaseList[iphase];
-        plogf("%-12.12s |",VPhase->PhaseName.c_str());
+        plogf("%-12.12s |",VPhase->PhaseName);
         plogf("%10.3e |", m_tPhaseMoles_old[iphase]*molScale);
         totalMoles += m_tPhaseMoles_old[iphase];
         if (m_tPhaseMoles_old[iphase] != VPhase->totalMoles() &&
@@ -263,7 +263,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     plogf("         Actual                    Target         Type      ElActive\n");
     for (size_t i = 0; i < m_numElemConstraints; ++i) {
         writeline(' ', 26, false);
-        plogf("%-2.2s", m_elementName[i].c_str());
+        plogf("%-2.2s", m_elementName[i]);
         plogf("%20.12E  %20.12E", m_elemAbundances[i]*molScale, m_elemAbundancesGoal[i]*molScale);
         plogf("   %3d     %3d\n", m_elType[i], m_elementActive[i]);
     }
@@ -286,7 +286,7 @@ int VCS_SOLVE::vcs_report(int iconv)
     for (size_t i = 0; i < nspecies; ++i) {
         size_t l = sortindex[i];
         size_t pid = m_phaseID[l];
-        plogf(" %-12.12s", m_speciesName[l].c_str());
+        plogf(" %-12.12s", m_speciesName[l]);
         plogf(" %14.7E ", m_molNumSpecies_old[l]*molScale);
         plogf("%14.7E  ", m_SSfeSpecies[l]);
         plogf("%14.7E  ", log(m_actCoeffSpecies_old[l]));
diff --git a/src/equil/vcs_rxnadj.cpp b/src/equil/vcs_rxnadj.cpp
index ef2e14bf3..7845feb4a 100644
--- a/src/equil/vcs_rxnadj.cpp
+++ b/src/equil/vcs_rxnadj.cpp
@@ -132,7 +132,7 @@ size_t VCS_SOLVE::vcs_RxnStepSizes(int& forceComponentCalc, size_t& kSpecial)
                     if (DEBUG_MODE_ENABLED) {
                         sprintf(ANOTE, "Skipped: superconverged DG = %11.3E", m_deltaGRxn_new[irxn]);
                         if (m_debug_print_lvl >= 2) {
-                            plogf("   --- %-12.12s", m_speciesName[kspec].c_str());
+                            plogf("   --- %-12.12s", m_speciesName[kspec]);
                             plogf("  %12.4E %12.4E %12.4E | %s\n",
                                   m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec],
                                   m_deltaGRxn_new[irxn], ANOTE);
@@ -148,7 +148,7 @@ size_t VCS_SOLVE::vcs_RxnStepSizes(int& forceComponentCalc, size_t& kSpecial)
                     if (DEBUG_MODE_ENABLED) {
                         sprintf(ANOTE, "Skipped: IC = %3d and DG >0: %11.3E", m_speciesStatus[kspec], m_deltaGRxn_new[irxn]);
                         if (m_debug_print_lvl >= 2) {
-                            plogf("   --- %-12.12s", m_speciesName[kspec].c_str());
+                            plogf("   --- %-12.12s", m_speciesName[kspec]);
                             plogf("  %12.4E %12.4E %12.4E | %s\n",
                                   m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec],
                                   m_deltaGRxn_new[irxn], ANOTE);
@@ -286,7 +286,7 @@ size_t VCS_SOLVE::vcs_RxnStepSizes(int& forceComponentCalc, size_t& kSpecial)
                             }
                             m_deltaMolNumSpecies[kspec] = -m_molNumSpecies_old[kspec];
                             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                                plogf("   --- %-12.12s", m_speciesName[kspec].c_str());
+                                plogf("   --- %-12.12s", m_speciesName[kspec]);
                                 plogf("  %12.4E %12.4E %12.4E | %s\n",
                                       m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec],
                                       m_deltaGRxn_new[irxn], ANOTE);
@@ -315,12 +315,12 @@ size_t VCS_SOLVE::vcs_RxnStepSizes(int& forceComponentCalc, size_t& kSpecial)
                                 sprintf(ANOTE, "Delete this SS phase %lu - SS components only", iphDel);
                             }
                             if (m_debug_print_lvl >= 2) {
-                                plogf("   --- %-12.12s", m_speciesName[kspec].c_str());
+                                plogf("   --- %-12.12s", m_speciesName[kspec]);
                                 plogf("  %12.4E %12.4E %12.4E | %s\n",
                                       m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec],
                                       m_deltaGRxn_new[irxn], ANOTE);
                                 plogf("   --- vcs_RxnStepSizes Special section to set up to delete %s",
-                                      m_speciesName[k].c_str());
+                                      m_speciesName[k]);
                                 plogendl();
                             }
                         }
@@ -340,7 +340,7 @@ size_t VCS_SOLVE::vcs_RxnStepSizes(int& forceComponentCalc, size_t& kSpecial)
                 }
             } /* End of regular processing */
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                plogf("   --- %-12.12s", m_speciesName[kspec].c_str());
+                plogf("   --- %-12.12s", m_speciesName[kspec]);
                 plogf("  %12.4E %12.4E %12.4E | %s\n",
                       m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec],
                       m_deltaGRxn_new[irxn], ANOTE);
@@ -416,7 +416,7 @@ int VCS_SOLVE::vcs_rxn_adj_cg()
                 if (DEBUG_MODE_ENABLED) {
                     sprintf(ANOTE, "Skipped: converged DG = %11.3E\n", m_deltaGRxn_new[irxn]);
                     plogf("   --- ");
-                    plogf("%-12.12s", m_speciesName[kspec].c_str());
+                    plogf("%-12.12s", m_speciesName[kspec]);
                     plogf("  %12.4E %12.4E | %s\n", m_molNumSpecies_old[kspec],
                           m_deltaMolNumSpecies[kspec], ANOTE);
                 }
@@ -430,7 +430,7 @@ int VCS_SOLVE::vcs_rxn_adj_cg()
                 if (DEBUG_MODE_ENABLED) {
                     sprintf(ANOTE, "Skipped: IC = %3d and DG >0: %11.3E\n", m_speciesStatus[kspec], m_deltaGRxn_new[irxn]);
                     plogf("   --- ");
-                    plogf("%-12.12s", m_speciesName[kspec].c_str());
+                    plogf("%-12.12s", m_speciesName[kspec]);
                     plogf("  %12.4E %12.4E | %s\n", m_molNumSpecies_old[kspec],
                           m_deltaMolNumSpecies[kspec], ANOTE);
                 }
@@ -515,7 +515,7 @@ int VCS_SOLVE::vcs_rxn_adj_cg()
                     m_tPhaseMoles_old[m_phaseID[k]] = 0.0;
                     if (DEBUG_MODE_ENABLED) {
                         plogf("   --- vcs_st2 Special section to delete ");
-                        plogf("%-12.12s", m_speciesName[k].c_str());
+                        plogf("%-12.12s", m_speciesName[k]);
                         plogf("\n   ---   Immediate return - Restart iteration\n");
                     }
                     /*
@@ -534,7 +534,7 @@ int VCS_SOLVE::vcs_rxn_adj_cg()
         } /* End of regular processing */
         if (DEBUG_MODE_ENABLED) {
             plogf("   --- ");
-            plogf("%-12.12s", m_speciesName[kspec].c_str());
+            plogf("%-12.12s", m_speciesName[kspec]);
             plogf("  %12.4E %12.4E | %s\n", m_molNumSpecies_old[kspec],
                   m_deltaMolNumSpecies[kspec], ANOTE);
         }
diff --git a/src/equil/vcs_setMolesLinProg.cpp b/src/equil/vcs_setMolesLinProg.cpp
index 43065df24..49d19d879 100644
--- a/src/equil/vcs_setMolesLinProg.cpp
+++ b/src/equil/vcs_setMolesLinProg.cpp
@@ -23,7 +23,7 @@ static void printProgress(const vector<string> &spName,
     plogf(" ---                   Name           Moles  -       SSGibbs \n");
     plogf(" -------------------------------------------------------------------------------------\n");
     for (size_t k = 0; k < soln.size(); k++) {
-        plogf(" ---      %20s %12.4g  - %12.4g\n", spName[k].c_str(), soln[k], ff[k]);
+        plogf(" ---      %20s %12.4g  - %12.4g\n", spName[k], soln[k], ff[k]);
         sum += soln[k] * ff[k];
     }
     plogf(" ---  Total sum to be minimized = %g\n", sum);
@@ -130,7 +130,7 @@ int VCS_SOLVE::vcs_setMolesLinProg()
                     // with a new set of components
                     if (!redo && delta_xi < 1.0e-10 && (m_molNumSpecies_old[ik] >= 1.0E-10)) {
                         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                            plogf("   --- Component too small: %s\n", m_speciesName[jcomp].c_str());
+                            plogf("   --- Component too small: %s\n", m_speciesName[jcomp]);
                         }
                         redo = true;
                     }
diff --git a/src/equil/vcs_solve.cpp b/src/equil/vcs_solve.cpp
index df98c3c08..8e6cb5335 100644
--- a/src/equil/vcs_solve.cpp
+++ b/src/equil/vcs_solve.cpp
@@ -73,17 +73,17 @@ void VCS_SOLVE::vcs_initSizes(const size_t nspecies0, const size_t nelements,
 
     string ser = "VCS_SOLVE: ERROR:\n\t";
     if (nspecies0 <= 0) {
-        plogf("%s Number of species is nonpositive\n", ser.c_str());
+        plogf("%s Number of species is nonpositive\n", ser);
         throw CanteraError("VCS_SOLVE()", ser +
                            " Number of species is nonpositive\n");
     }
     if (nelements <= 0) {
-        plogf("%s Number of elements is nonpositive\n", ser.c_str());
+        plogf("%s Number of elements is nonpositive\n", ser);
         throw CanteraError("VCS_SOLVE()", ser +
                            " Number of species is nonpositive\n");
     }
     if (nphase0 <= 0) {
-        plogf("%s Number of phases is nonpositive\n", ser.c_str());
+        plogf("%s Number of phases is nonpositive\n", ser);
         throw CanteraError("VCS_SOLVE()", ser +
                            " Number of species is nonpositive\n");
     }
@@ -429,7 +429,7 @@ int VCS_SOLVE::vcs_prob_specifyFully(const VCS_PROB* pub)
         }
         if (!nonzero) {
             plogf("vcs_prob_specifyFully:: species %d %s has a zero formula matrix!\n", i,
-                  pub->SpName[i].c_str());
+                  pub->SpName[i]);
             return VCS_PUB_BAD;
         }
     }
@@ -595,7 +595,7 @@ int VCS_SOLVE::vcs_prob_specifyFully(const VCS_PROB* pub)
             vcs_VolPhase* Vphase = pub->VPhaseList[iph];
             if (numPhSp[iph] != Vphase->nSpecies()) {
                 plogf("%sNumber of species in phase %d, %s, doesn't match\n",
-                      ser, iph, Vphase->PhaseName.c_str());
+                      ser, iph, Vphase->PhaseName);
                 return VCS_PUB_BAD;
             }
         }
@@ -644,7 +644,7 @@ int VCS_SOLVE::vcs_prob_specifyFully(const VCS_PROB* pub)
                 } else {
                     if (m_debug_print_lvl >= 2) {
                         plogf("Charge neutrality condition %s not zero, %g. Setting it zero\n",
-                              m_elementName[i].c_str(), m_elemAbundancesGoal[i]);
+                              m_elementName[i], m_elemAbundancesGoal[i]);
                     }
                     m_elemAbundancesGoal[i] = 0.0;
                 }
@@ -782,38 +782,34 @@ int VCS_SOLVE::vcs_prob_specify(const VCS_PROB* pub)
         vcs_VolPhase* pub_phase_ptr = pub->VPhaseList[iph];
 
         if (vPhase->VP_ID_ != pub_phase_ptr->VP_ID_) {
-            plogf("%sPhase numbers have changed:%d %d\n", yo.c_str(),
-                  vPhase->VP_ID_, pub_phase_ptr->VP_ID_);
+            plogf("%sPhase numbers have changed:%d %d\n",
+                  yo, vPhase->VP_ID_, pub_phase_ptr->VP_ID_);
             retn = VCS_PUB_BAD;
         }
 
         if (vPhase->m_singleSpecies != pub_phase_ptr->m_singleSpecies) {
-            plogf("%sSingleSpecies value have changed:%d %d\n", yo.c_str(),
-                  vPhase->m_singleSpecies,
-                  pub_phase_ptr->m_singleSpecies);
+            plogf("%sSingleSpecies value have changed:%d %d\n",
+                  yo, vPhase->m_singleSpecies, pub_phase_ptr->m_singleSpecies);
             retn = VCS_PUB_BAD;
         }
 
         if (vPhase->m_gasPhase != pub_phase_ptr->m_gasPhase) {
-            plogf("%sGasPhase value have changed:%d %d\n", yo.c_str(),
-                  vPhase->m_gasPhase,
-                  pub_phase_ptr->m_gasPhase);
+            plogf("%sGasPhase value have changed:%d %d\n",
+                  yo, vPhase->m_gasPhase, pub_phase_ptr->m_gasPhase);
             retn = VCS_PUB_BAD;
         }
 
         vPhase->m_eqnState = pub_phase_ptr->m_eqnState;
 
         if (vPhase->nSpecies() != pub_phase_ptr->nSpecies()) {
-            plogf("%sNVolSpecies value have changed:%d %d\n", yo.c_str(),
-                  vPhase->nSpecies(),
-                  pub_phase_ptr->nSpecies());
+            plogf("%sNVolSpecies value have changed:%d %d\n",
+                  yo, vPhase->nSpecies(), pub_phase_ptr->nSpecies());
             retn = VCS_PUB_BAD;
         }
 
         if (vPhase->PhaseName != pub_phase_ptr->PhaseName) {
-            plogf("%sPhaseName value have changed:%s %s\n", yo.c_str(),
-                  vPhase->PhaseName.c_str(),
-                  pub_phase_ptr->PhaseName.c_str());
+            plogf("%sPhaseName value have changed:%s %s\n",
+                  yo, vPhase->PhaseName, pub_phase_ptr->PhaseName);
             retn = VCS_PUB_BAD;
         }
 
diff --git a/src/equil/vcs_solve_TP.cpp b/src/equil/vcs_solve_TP.cpp
index 54c482430..49f04b6ea 100644
--- a/src/equil/vcs_solve_TP.cpp
+++ b/src/equil/vcs_solve_TP.cpp
@@ -105,7 +105,7 @@ int VCS_SOLVE::vcs_solve_TP(int print_lvl, int printDetails, int maxit)
     /* ******************************************************* */
     if (print_lvl != 0) {
         plogf("VCS CALCULATION METHOD\n\n ");
-        plogf("%s\n", m_title.c_str());
+        plogf("%s\n", m_title);
         plogf("\n\n%5d SPECIES\n%5d ELEMENTS\n", m_numSpeciesTot, m_numElemConstraints);
         plogf("%5d COMPONENTS\n", m_numComponents);
         plogf("%5d PHASES\n", m_numPhases);
@@ -122,7 +122,7 @@ int VCS_SOLVE::vcs_solve_TP(int print_lvl, int printDetails, int maxit)
         plogf("          FROM ESTIMATE           Type\n\n");
         for (size_t i = 0; i < m_numElemConstraints; ++i) {
             writeline(' ', 26, false);
-            plogf("%-2.2s", m_elementName[i].c_str());
+            plogf("%-2.2s", m_elementName[i]);
             plogf("%20.12E%20.12E     %3d\n", m_elemAbundancesGoal[i], m_elemAbundances[i],
                   m_elType[i]);
         }
@@ -154,12 +154,12 @@ int VCS_SOLVE::vcs_solve_TP(int print_lvl, int printDetails, int maxit)
         plogf("   STAN_CHEM_POT  EQUILIBRIUM_EST.  Species_Type\n\n");
         writeline(' ', 20, false);
         for (size_t i = 0; i < m_numElemConstraints; ++i) {
-            plogf("%-4.4s    ", m_elementName[i].c_str());
+            plogf("%-4.4s    ", m_elementName[i]);
         }
         plogf("   PhaseID\n");
         double RT = vcs_nondimMult_TP(m_VCS_UnitsFormat, m_temperature);
         for (size_t i = 0; i < m_numSpeciesTot; ++i) {
-            plogf(" %-18.18s", m_speciesName[i].c_str());
+            plogf(" %-18.18s", m_speciesName[i]);
             for (size_t j = 0; j < m_numElemConstraints; ++j) {
                 plogf("% -7.3g ", m_formulaMatrix(i,j));
             }
@@ -179,9 +179,8 @@ int VCS_SOLVE::vcs_solve_TP(int print_lvl, int printDetails, int maxit)
 
     for (size_t i = 0; i < m_numSpeciesTot; ++i) {
         if (m_molNumSpecies_old[i] < 0.0) {
-            plogf("On Input species %-12s has a "
-                  "negative MF, setting it small",
-                  m_speciesName[i].c_str());
+            plogf("On Input species %-12s has a negative MF, setting it small",
+                  m_speciesName[i]);
             plogendl();
             size_t iph = m_phaseID[i];
             double tmp = m_tPhaseMoles_old[iph] * VCS_RELDELETE_SPECIES_CUTOFF * 10;
@@ -620,7 +619,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                 bool resurrect = (m_deltaMolNumSpecies[kspec] > 0.0);
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 3) {
                     plogf("   --- %s currently zeroed (SpStatus=%-2d):",
-                          m_speciesName[kspec].c_str(), m_speciesStatus[kspec]);
+                          m_speciesName[kspec], m_speciesStatus[kspec]);
                     plogf("%3d DG = %11.4E WT = %11.4E W = %11.4E DS = %11.4E\n",
                           irxn, m_deltaGRxn_new[irxn], m_molNumSpecies_new[kspec],
                           m_molNumSpecies_old[kspec], m_deltaMolNumSpecies[kspec]);
@@ -669,14 +668,14 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                     if (Vphase->exists() == VCS_PHASE_EXIST_NO) {
                         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                             plogf("   --- Zeroed species changed to major: ");
-                            plogf("%-12s\n", m_speciesName[kspec].c_str());
+                            plogf("%-12s\n", m_speciesName[kspec]);
                         }
                         m_speciesStatus[kspec] = VCS_SPECIES_MAJOR;
                         allMinorZeroedSpecies = false;
                     } else {
                         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                             plogf("   --- Zeroed species changed to minor: ");
-                            plogf("%-12s\n", m_speciesName[kspec].c_str());
+                            plogf("%-12s\n", m_speciesName[kspec]);
                         }
                         m_speciesStatus[kspec] = VCS_SPECIES_MINOR;
                     }
@@ -712,7 +711,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                         sprintf(ANOTE,"minor species not considered");
                         if (m_debug_print_lvl >= 2) {
                             plogf("   --- ");
-                            plogf("%-12s", m_speciesName[kspec].c_str());
+                            plogf("%-12s", m_speciesName[kspec]);
                             plogf("%3d%11.4E%11.4E%11.4E | %s",
                                   m_speciesStatus[kspec], m_molNumSpecies_old[kspec], m_molNumSpecies_new[kspec],
                                   m_deltaMolNumSpecies[kspec], ANOTE);
@@ -746,7 +745,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                     /*******************************************************************/
                     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                         plogf("   --- Delete minor species in multispec phase: %-12s",
-                              m_speciesName[kspec].c_str());
+                              m_speciesName[kspec]);
                         plogendl();
                     }
                     m_deltaMolNumSpecies[kspec] = 0.0;
@@ -792,7 +791,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                         sprintf(ANOTE, "major species is converged");
                         if (m_debug_print_lvl >= 2) {
                             plogf("   --- ");
-                            plogf("%-12s", m_speciesName[kspec].c_str());
+                            plogf("%-12s", m_speciesName[kspec]);
                             plogf("%3d%11.4E%11.4E%11.4E | %s",
                                   m_speciesStatus[kspec], m_molNumSpecies_old[kspec], m_molNumSpecies_new[kspec],
                                   m_deltaMolNumSpecies[kspec], ANOTE);
@@ -910,7 +909,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                                 doPhaseDeleteKspec = kspec;
                                 if (m_debug_print_lvl >= 2 && m_speciesStatus[kspec] >= 0) {
                                     plogf("   --- SS species changed to zeroedss: ");
-                                    plogf("%-12s", m_speciesName[kspec].c_str());
+                                    plogf("%-12s", m_speciesName[kspec]);
                                     plogendl();
                                 }
                             }
@@ -974,7 +973,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
             if (m_debug_print_lvl >= 2) {
                 m_molNumSpecies_new[kspec] = m_molNumSpecies_old[kspec] + m_deltaMolNumSpecies[kspec];
                 plogf("   --- ");
-                plogf("%-12.12s", m_speciesName[kspec].c_str());
+                plogf("%-12.12s", m_speciesName[kspec]);
                 plogf("%3d%11.4E%11.4E%11.4E | %s",
                       m_speciesStatus[kspec], m_molNumSpecies_old[kspec],
                       m_molNumSpecies_new[kspec],
@@ -986,7 +985,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                     plogf("   --- ");
                     plogf("%-12.12s Main Loop Special Case deleting phase with species: ",
-                          m_speciesName[doPhaseDeleteKspec].c_str());
+                          m_speciesName[doPhaseDeleteKspec]);
                     plogendl();
                 }
                 break;
@@ -995,7 +994,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
             for (size_t k = 0; k < m_numComponents; k++) {
                 plogf("   --- ");
-                plogf("%-12.12s", m_speciesName[k].c_str());
+                plogf("%-12.12s", m_speciesName[k]);
                 plogf("  c%11.4E%11.4E%11.4E |\n",
                       m_molNumSpecies_old[k],
                       m_molNumSpecies_old[k]+m_deltaMolNumSpecies[k], m_deltaMolNumSpecies[k]);
@@ -1038,7 +1037,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
             par *= 0.99;
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                 plogf("   --- Reduction in step size due to component ");
-                plogf("%s", m_speciesName[ll].c_str());
+                plogf("%s", m_speciesName[ll]);
                 plogf(" going negative = %11.3E", par);
                 plogendl();
             }
@@ -1123,13 +1122,13 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
             plogf("   --- SPECIES Status INIT MOLES TENT_MOLES");
             plogf("  FINAL KMOLES  INIT_DEL_G/RT  TENT_DEL_G/RT  FINAL_DELTA_G/RT\n");
             for (size_t i = 0; i < m_numComponents; ++i) {
-                plogf("  --- %-12.12s", m_speciesName[i].c_str());
+                plogf("  --- %-12.12s", m_speciesName[i]);
                 plogf("    %14.6E %14.6E %14.6E\n", m_molNumSpecies_old[i],
                       m_molNumSpecies_old[i] + m_deltaMolNumSpecies[i], m_molNumSpecies_new[i]);
             }
             for (size_t kspec = m_numComponents; kspec < m_numSpeciesRdc; ++kspec) {
                 size_t irxn = kspec - m_numComponents;
-                plogf("  --- %-12.12s", m_speciesName[kspec].c_str());
+                plogf("  --- %-12.12s", m_speciesName[kspec]);
                 plogf(" %2d %14.6E%14.6E%14.6E%14.6E%14.6E%14.6E\n", m_speciesStatus[kspec],
                       m_molNumSpecies_old[kspec],
                       m_molNumSpecies_old[kspec]+m_deltaMolNumSpecies[kspec],
@@ -1173,14 +1172,14 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
         plogf("   ---      Species Status Initial_KMoles Final_KMoles Initial_Mu/RT");
         plogf("     Mu/RT     Init_Del_G/RT   Delta_G/RT\n");
         for (size_t i = 0; i < m_numComponents; ++i) {
-            plogf("   ---   %-12.12s", m_speciesName[i].c_str());
+            plogf("   ---   %-12.12s", m_speciesName[i]);
             plogf("    ");
             plogf("%14.6E%14.6E%14.6E%14.6E\n", m_molNumSpecies_old[i],
                   m_molNumSpecies_new[i], m_feSpecies_old[i], m_feSpecies_new[i]);
         }
         for (size_t i = m_numComponents; i < m_numSpeciesRdc; ++i) {
             size_t l1 = i - m_numComponents;
-            plogf("   ---   %-12.12s", m_speciesName[i].c_str());
+            plogf("   ---   %-12.12s", m_speciesName[i]);
             plogf(" %2d %14.6E%14.6E%14.6E%14.6E%14.6E%14.6E\n",
                   m_speciesStatus[i], m_molNumSpecies_old[i],
                   m_molNumSpecies_new[i], m_feSpecies_old[i], m_feSpecies_new[i],
@@ -1188,7 +1187,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
         }
         for (size_t kspec = m_numSpeciesRdc; kspec < m_numSpeciesTot; ++kspec) {
             size_t l1 = kspec - m_numComponents;
-            plogf("   ---   %-12.12s", m_speciesName[kspec].c_str());
+            plogf("   ---   %-12.12s", m_speciesName[kspec]);
             plogf(" %2d %14.6E%14.6E%14.6E%14.6E%14.6E%14.6E\n",
                   m_speciesStatus[kspec], m_molNumSpecies_old[kspec],
                   m_molNumSpecies_new[kspec], m_feSpecies_old[kspec], m_feSpecies_new[kspec],
@@ -1206,7 +1205,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
         writeline('-', 50);
         for (size_t iph = 0; iph < m_numPhases; iph++) {
             vcs_VolPhase* Vphase = m_VolPhaseList[iph];
-            plogf("   ---   %18s = %15.7E\n", Vphase->PhaseName.c_str(), m_tPhaseMoles_new[iph]);
+            plogf("   ---   %18s = %15.7E\n", Vphase->PhaseName, m_tPhaseMoles_new[iph]);
         }
         plogf("   ");
         writeline('-', 103);
@@ -1350,9 +1349,9 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
             if (doSwap && m_stoichCoeffRxnMatrix(j,i) != 0.0) {
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                     plogf("   --- Get a new basis because ");
-                    plogf("%s", m_speciesName[l].c_str());
+                    plogf("%s", m_speciesName[l]);
                     plogf(" is better than comp ");
-                    plogf("%s", m_speciesName[j].c_str());
+                    plogf("%s", m_speciesName[j]);
                     plogf(" and share nonzero stoic: %-9.1f",
                           m_stoichCoeffRxnMatrix(j,i));
                     plogendl();
@@ -1387,7 +1386,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
         if (speciesType < VCS_SPECIES_MINOR) {
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2 && m_speciesStatus[kspec] >= VCS_SPECIES_MINOR) {
                 plogf("   ---    major/minor species is now zeroed out: %s\n",
-                      m_speciesName[kspec].c_str());
+                      m_speciesName[kspec]);
             }
             ++m_numRxnMinorZeroed;
         } else if (speciesType == VCS_SPECIES_MINOR) {
@@ -1400,7 +1399,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                     plogf("   ---   Zeroed Species turned into a "
                           "minor species: ");
                 }
-                plogf("%s\n", m_speciesName[kspec].c_str());
+                plogf("%s\n", m_speciesName[kspec]);
             }
             ++m_numRxnMinorZeroed;
         } else if (speciesType == VCS_SPECIES_MAJOR) {
@@ -1413,7 +1412,7 @@ void VCS_SOLVE::solve_tp_inner(size_t& iti, size_t& it1,
                     } else {
                         plogf("   ---   Noncomponent turned from zeroed to major: ");
                     }
-                    plogf("%s\n", m_speciesName[kspec].c_str());
+                    plogf("%s\n", m_speciesName[kspec]);
                 }
                 m_speciesStatus[kspec] = VCS_SPECIES_MAJOR;
             }
@@ -1449,7 +1448,7 @@ void VCS_SOLVE::solve_tp_equilib_check(bool& allMinorZeroedSpecies,
                     stage = RETURN_A;
                 } else {
                     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                        plogf("%s failed\n", m_speciesName[m_indexRxnToSpecies[irxn]].c_str());
+                        plogf("%s failed\n", m_speciesName[m_indexRxnToSpecies[irxn]]);
                     }
                     // Convergence amongst major species has not been achieved
                     /*
@@ -1502,7 +1501,7 @@ void VCS_SOLVE::solve_tp_equilib_check(bool& allMinorZeroedSpecies,
                     return;
                 }
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                    plogf("%s failed\n", m_speciesName[m_indexRxnToSpecies[irxn]].c_str());
+                    plogf("%s failed\n", m_speciesName[m_indexRxnToSpecies[irxn]]);
                 }
                 /*
                  *  Set iti to zero to force a full calculation, and go back
@@ -1894,7 +1893,7 @@ void VCS_SOLVE::vcs_reinsert_deleted(size_t kspec)
 {
     size_t iph = m_phaseID[kspec];
     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-        plogf("   --- Add back a deleted species: %-12s\n", m_speciesName[kspec].c_str());
+        plogf("   --- Add back a deleted species: %-12s\n", m_speciesName[kspec]);
     }
     /*
      * Set the species back to minor species status
@@ -1957,7 +1956,7 @@ bool VCS_SOLVE::vcs_delete_multiphase(const size_t iph)
      */
     Vphase->setTotalMoles(0.0);
     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-        plogf("   --- delete_multiphase %d, %s\n", iph, Vphase->PhaseName.c_str());
+        plogf("   --- delete_multiphase %d, %s\n", iph, Vphase->PhaseName);
     }
 
     /*
@@ -1977,7 +1976,7 @@ bool VCS_SOLVE::vcs_delete_multiphase(const size_t iph)
                     successful = false;
                     if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                         plogf("   --- delete_multiphase %d, %s ERROR problems deleting species %s\n",
-                              iph, Vphase->PhaseName.c_str(), m_speciesName[kspec].c_str());
+                              iph, Vphase->PhaseName, m_speciesName[kspec]);
                         plogf("   ---     delta  attempted: %g  achieved: %g   "
                               "  Zeroing it manually\n", dx, dxTent);
                     }
@@ -2008,7 +2007,7 @@ bool VCS_SOLVE::vcs_delete_multiphase(const size_t iph)
         if (m_phaseID[kcomp] == iph) {
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                 plogf("   --- delete_multiphase   One of the species is a component %d - %s with mole number %g\n",
-                      kcomp, m_speciesName[kcomp].c_str(), m_molNumSpecies_old[kcomp]);
+                      kcomp, m_speciesName[kcomp], m_molNumSpecies_old[kcomp]);
             }
             if (m_molNumSpecies_old[kcomp] != 0.0) {
                 for (size_t kspec = m_numComponents; kspec < m_numSpeciesRdc; ++kspec) {
@@ -2045,7 +2044,7 @@ bool VCS_SOLVE::vcs_delete_multiphase(const size_t iph)
             if (m_molNumSpecies_old[kcomp] != 0.0) {
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                     plogf("   --- delete_multiphase   One of the species is a component %d - %s still with mole number %g\n",
-                          kcomp, m_speciesName[kcomp].c_str(), m_molNumSpecies_old[kcomp]);
+                          kcomp, m_speciesName[kcomp], m_molNumSpecies_old[kcomp]);
                     plogf("   ---                     zeroing it \n");
                 }
                 m_molNumSpecies_old[kcomp] = 0.0;
@@ -2073,7 +2072,7 @@ bool VCS_SOLVE::vcs_delete_multiphase(const size_t iph)
             ++m_numRxnRdc;
             ++m_numSpeciesRdc;
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                plogf("   ---    Make %s", m_speciesName[kspec].c_str());
+                plogf("   ---    Make %s", m_speciesName[kspec]);
                 plogf(" an active but zeroed species because its phase "
                       "was zeroed\n");
             }
@@ -2264,21 +2263,21 @@ size_t VCS_SOLVE::vcs_add_all_deleted()
             if (retn == 0) {
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl) {
                     plogf("  --- add_deleted(): delta_species() failed for species %s (%d) with mol number %g\n",
-                          m_speciesName[kspec].c_str(), kspec, dx);
+                          m_speciesName[kspec], kspec, dx);
                 }
                 if (dx > 1.0E-50) {
                     dx = 1.0E-50;
                     retn = delta_species(kspec, &dx);
                     if (DEBUG_MODE_ENABLED && retn == 0 && m_debug_print_lvl) {
                         plogf("  --- add_deleted(): delta_species() failed for species %s (%d) with mol number %g\n",
-                              m_speciesName[kspec].c_str(), kspec, dx);
+                              m_speciesName[kspec], kspec, dx);
                     }
                 }
             }
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                 if (retn != 0) {
                     plogf("  --- add_deleted():  species %s added back in with mol number %g",
-                          m_speciesName[kspec].c_str(), dx);
+                          m_speciesName[kspec], dx);
                     plogendl();
                 } else {
                     plogf("  --- add_deleted():  species %s failed to be added  back in");
@@ -2302,7 +2301,7 @@ size_t VCS_SOLVE::vcs_add_all_deleted()
                 retn++;
                 if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                     plogf("  --- add_deleted():  species %s with mol number %g not converged: DG = %g",
-                          m_speciesName[kspec].c_str(), m_molNumSpecies_old[kspec],
+                          m_speciesName[kspec], m_molNumSpecies_old[kspec],
                           m_deltaGRxn_old[irxn]);
                     plogendl();
                 }
@@ -2693,13 +2692,13 @@ int VCS_SOLVE::vcs_basopt(const bool doJustComponents, double aw[], double sa[],
         /* ****************************************** */
         if (jr != k) {
             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-                plogf("   ---   %-12.12s", m_speciesName[k].c_str());
+                plogf("   ---   %-12.12s", m_speciesName[k]);
                 if (m_speciesUnknownType[k] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                    plogf("(Volts = %9.2g)", m_molNumSpecies_old[k]);
                 } else {
                    plogf("(%9.2g)", m_molNumSpecies_old[k]);
                 }
-                plogf(" replaces %-12.12s", m_speciesName[jr].c_str());
+                plogf(" replaces %-12.12s", m_speciesName[jr]);
                 if (m_speciesUnknownType[jr] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                    plogf("(Volts = %9.2g)", m_molNumSpecies_old[jr]);
                 } else {
@@ -2710,7 +2709,7 @@ int VCS_SOLVE::vcs_basopt(const bool doJustComponents, double aw[], double sa[],
             vcs_switch_pos(false, jr, k);
             std::swap(aw[jr], aw[k]);
         } else if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
-            plogf("   ---   %-12.12s", m_speciesName[k].c_str());
+            plogf("   ---   %-12.12s", m_speciesName[k]);
             if (m_speciesUnknownType[k] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("(Volts = %9.2g) remains            ", m_molNumSpecies_old[k]);
             } else {
@@ -2862,12 +2861,12 @@ L_END_LOOP:
         }
         plogf("\n   ---   NonComponent|   Moles  |");
         for (size_t j = 0; j < ncTrial; j++) {
-            plogf(" %10.10s", m_speciesName[j].c_str());
+            plogf(" %10.10s", m_speciesName[j]);
         }
         plogf("\n");
         for (size_t i = 0; i < m_numRxnTot; i++) {
             plogf("   --- %3d ", m_indexRxnToSpecies[i]);
-            plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[i]].c_str());
+            plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[i]]);
             if (m_speciesUnknownType[m_indexRxnToSpecies[i]] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("|% -10.3E|", 0.0);
             } else {
@@ -2919,9 +2918,9 @@ L_END_LOOP:
             }
         }
         plogf("   ---               largest error in Stoich coeff = %g at rxn = %d ", sumMax, iMax);
-        plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[iMax]].c_str());
+        plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[iMax]]);
         plogf(" element = %d ", jMax);
-        plogf("%-5.5s", m_elementName[jMax].c_str());
+        plogf("%-5.5s", m_elementName[jMax]);
         plogf("\n");
         plogf("   ");
         for (size_t i=0; i<77; i++) {
@@ -3058,7 +3057,7 @@ int VCS_SOLVE::vcs_species_type(const size_t kspec) const
                         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                             plogf("   ---   %s can not be nonzero because"
                                   " needed element %s is zero\n",
-                                  m_speciesName[kspec].c_str(), m_elementName[j].c_str());
+                                  m_speciesName[kspec], m_elementName[j]);
                         }
                         if (m_SSPhase[kspec]) {
                             return VCS_SPECIES_ZEROEDSS;
@@ -3087,7 +3086,7 @@ int VCS_SOLVE::vcs_species_type(const size_t kspec) const
                             if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 2) {
                                 plogf("   ---   %s is prevented from popping into existence because"
                                       " a needed component to be consumed, %s, has a zero mole number\n",
-                                      m_speciesName[kspec].c_str(), m_speciesName[j].c_str());
+                                      m_speciesName[kspec], m_speciesName[j]);
                             }
                             if (m_SSPhase[kspec]) {
                                 return VCS_SPECIES_ZEROEDSS;
@@ -3103,7 +3102,7 @@ int VCS_SOLVE::vcs_species_type(const size_t kspec) const
                                 plogf("   ---   %s is prevented from popping into existence because"
                                       " a needed component %s is in a zeroed-phase that would be "
                                       "popped into existence at the same time\n",
-                                      m_speciesName[kspec].c_str(), m_speciesName[j].c_str());
+                                      m_speciesName[kspec], m_speciesName[j]);
                             }
                             if (m_SSPhase[kspec]) {
                                 return VCS_SPECIES_ZEROEDSS;
@@ -3284,7 +3283,7 @@ void VCS_SOLVE::vcs_dfe(const int stateCalc,
         if (ll == 0) {
             if (lbot != 0) {
                 plogf("   --- Subroutine vcs_dfe called for one species: ");
-                plogf("%-12.12s", m_speciesName[lbot].c_str());
+                plogf("%-12.12s", m_speciesName[lbot]);
             } else {
                 plogf("   --- Subroutine vcs_dfe called for all species");
             }
@@ -3583,7 +3582,7 @@ void VCS_SOLVE::prneav() const
     plogf(" Element   Now      Orignal      Deviation          Type\n");
     for (size_t j = 0; j < m_numElemConstraints; ++j) {
         plogf("  ");
-        plogf("%-2.2s", m_elementName[j].c_str());
+        plogf("%-2.2s", m_elementName[j]);
         plogf(" = %15.6E     %15.6E     %15.6E  %3d\n",
               eav[j], m_elemAbundancesGoal[j], eav[j] - m_elemAbundancesGoal[j], m_elType[j]);
         if (m_elemAbundancesGoal[j] != 0.) {
@@ -3700,7 +3699,7 @@ bool VCS_SOLVE::vcs_evaluate_speciesType()
     for (size_t kspec = 0; kspec < m_numSpeciesTot; ++kspec) {
         m_speciesStatus[kspec] = vcs_species_type(kspec);
         if (DEBUG_MODE_ENABLED && m_debug_print_lvl >= 5) {
-            plogf("  --- %-16s: ", m_speciesName[kspec].c_str());
+            plogf("  --- %-16s: ", m_speciesName[kspec]);
             if (kspec < m_numComponents) {
                 plogf("(COMP) ");
             } else {
@@ -3715,31 +3714,31 @@ bool VCS_SOLVE::vcs_evaluate_speciesType()
                 case VCS_SPECIES_COMPONENT:
                     break;
                 case VCS_SPECIES_MAJOR:
-                    plogf("  ---      Major Species          : %-s\n", m_speciesName[kspec].c_str());
+                    plogf("  ---      Major Species          : %-s\n", m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_ZEROEDPHASE:
                     plogf("  ---      Purposely Zeroed-Phase Species (not in problem): %-s\n",
-                          m_speciesName[kspec].c_str());
+                          m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_ZEROEDMS:
-                    plogf("  ---      Zeroed-MS Phase Species: %-s\n", m_speciesName[kspec].c_str());
+                    plogf("  ---      Zeroed-MS Phase Species: %-s\n", m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_ZEROEDSS:
-                    plogf("  ---      Zeroed-SS Phase Species: %-s\n", m_speciesName[kspec].c_str());
+                    plogf("  ---      Zeroed-SS Phase Species: %-s\n", m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_DELETED:
-                    plogf("  ---      Deleted-Small Species  : %-s\n", m_speciesName[kspec].c_str());
+                    plogf("  ---      Deleted-Small Species  : %-s\n", m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_ACTIVEBUTZERO:
                     plogf("  ---      Zeroed Species in an active MS phase (tmp): %-s\n",
-                          m_speciesName[kspec].c_str());
+                          m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_STOICHZERO:
                     plogf("  ---     Zeroed Species in an active MS phase (Stoich Constraint): %-s\n",
-                          m_speciesName[kspec].c_str());
+                          m_speciesName[kspec]);
                     break;
                 case VCS_SPECIES_INTERFACIALVOLTAGE:
-                    plogf("  ---      InterfaceVoltage Species: %-s\n", m_speciesName[kspec].c_str());
+                    plogf("  ---      InterfaceVoltage Species: %-s\n", m_speciesName[kspec]);
                     break;
                 default:
                     throw CanteraError("VCS_SOLVE::vcs_evaluate_speciesType",
@@ -3975,12 +3974,12 @@ void VCS_SOLVE::vcs_printDeltaG(const int stateCalc)
         }
         plogf("\n   ---   NonComponent|   Moles  |       ");
         for (size_t j = 0; j < m_numComponents; j++) {
-            plogf("%-10.10s", m_speciesName[j].c_str());
+            plogf("%-10.10s", m_speciesName[j]);
         }
         plogf("\n");
         for (size_t i = 0; i < m_numRxnTot; i++) {
             plogf("   --- %3d ", m_indexRxnToSpecies[i]);
-            plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[i]].c_str());
+            plogf("%-10.10s", m_speciesName[m_indexRxnToSpecies[i]]);
             if (m_speciesUnknownType[m_indexRxnToSpecies[i]] == VCS_SPECIES_TYPE_INTERFACIALVOLTAGE) {
                 plogf("|   NA     |");
             } else {
diff --git a/src/oneD/OneDim.cpp b/src/oneD/OneDim.cpp
index 76599ade5..c070a8df3 100644
--- a/src/oneD/OneDim.cpp
+++ b/src/oneD/OneDim.cpp
@@ -373,7 +373,7 @@ void OneDim::save(const std::string& fname, std::string id,
     struct tm* newtime = localtime(&aclock); // Convert time to struct tm form
 
     XML_Node root("ctml");
-    ifstream fin(fname.c_str());
+    ifstream fin(fname);
     if (fin) {
         root.build(fin);
         // Remove existing solution with the same id
@@ -395,7 +395,7 @@ void OneDim::save(const std::string& fname, std::string id,
         d->save(sim, sol);
         d = d->right();
     }
-    ofstream s(fname.c_str());
+    ofstream s(fname);
     if (!s) {
         throw CanteraError("OneDim::save","could not open file "+fname);
     }
diff --git a/src/oneD/Sim1D.cpp b/src/oneD/Sim1D.cpp
index 55bc3dba3..a531767ed 100644
--- a/src/oneD/Sim1D.cpp
+++ b/src/oneD/Sim1D.cpp
@@ -106,7 +106,7 @@ void Sim1D::saveResidual(const std::string& fname, const std::string& id,
 void Sim1D::restore(const std::string& fname, const std::string& id,
                     int loglevel)
 {
-    ifstream s(fname.c_str());
+    ifstream s(fname);
     if (!s) {
         throw CanteraError("Sim1D::restore",
                            "could not open input file "+fname);
diff --git a/src/thermo/IonsFromNeutralVPSSTP.cpp b/src/thermo/IonsFromNeutralVPSSTP.cpp
index f49693a21..4e10bbd96 100644
--- a/src/thermo/IonsFromNeutralVPSSTP.cpp
+++ b/src/thermo/IonsFromNeutralVPSSTP.cpp
@@ -155,7 +155,7 @@ void IonsFromNeutralVPSSTP::constructPhaseFile(std::string inputFile, std::strin
                            "input file is null");
     }
     string path = findInputFile(inputFile);
-    std::ifstream fin(path.c_str());
+    std::ifstream fin(path);
     if (!fin) {
         throw CanteraError("MargulesVPSSTP:constructPhaseFile","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/LatticePhase.cpp b/src/thermo/LatticePhase.cpp
index a42d7578f..9de3c430f 100644
--- a/src/thermo/LatticePhase.cpp
+++ b/src/thermo/LatticePhase.cpp
@@ -296,7 +296,6 @@ void LatticePhase::initThermoXML(XML_Node& phaseNode, const std::string& id_)
                            "ids don't match");
     }
 
-    std::string subname = "LatticePhase::initThermoXML";
     /*
      * Check on the thermo field. Must have:
      * <thermo model="Lattice" />
@@ -305,11 +304,11 @@ void LatticePhase::initThermoXML(XML_Node& phaseNode, const std::string& id_)
         XML_Node& thNode = phaseNode.child("thermo");
         std::string mString = thNode.attrib("model");
         if (lowercase(mString) != "lattice") {
-            throw CanteraError(subname.c_str(),
+            throw CanteraError("LatticePhase::initThermoXML",
                                "Unknown thermo model: " + mString);
         }
     } else {
-        throw CanteraError(subname.c_str(),
+        throw CanteraError("LatticePhase::initThermoXML",
                            "Unspecified thermo model");
     }
     /*
diff --git a/src/thermo/MolarityIonicVPSSTP.cpp b/src/thermo/MolarityIonicVPSSTP.cpp
index 166d909da..8c294234d 100644
--- a/src/thermo/MolarityIonicVPSSTP.cpp
+++ b/src/thermo/MolarityIonicVPSSTP.cpp
@@ -396,7 +396,7 @@ std::string MolarityIonicVPSSTP::report(bool show_thermo, doublereal threshold)
     fmt::MemoryWriter b;
     try {
         if (name() != "") {
-            b.write("\n  {}:\n", name().c_str());
+            b.write("\n  {}:\n", name());
         }
         b.write("\n");
         b.write("       temperature    {:12.6g}  K\n", temperature());
diff --git a/src/thermo/PDSS_ConstVol.cpp b/src/thermo/PDSS_ConstVol.cpp
index f468ecc36..e9463d0e3 100644
--- a/src/thermo/PDSS_ConstVol.cpp
+++ b/src/thermo/PDSS_ConstVol.cpp
@@ -104,7 +104,7 @@ void PDSS_ConstVol::constructPDSSFile(VPStandardStateTP* tp, size_t spindex,
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    ifstream fin(path.c_str());
+    ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_ConstVol::initThermo","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PDSS_HKFT.cpp b/src/thermo/PDSS_HKFT.cpp
index e96e3d360..f09539811 100644
--- a/src/thermo/PDSS_HKFT.cpp
+++ b/src/thermo/PDSS_HKFT.cpp
@@ -626,7 +626,7 @@ void PDSS_HKFT::constructPDSSFile(VPStandardStateTP* tp, size_t spindex,
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    ifstream fin(path.c_str());
+    ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_HKFT::initThermo","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PDSS_IdealGas.cpp b/src/thermo/PDSS_IdealGas.cpp
index 9879eafa1..bca02d48d 100644
--- a/src/thermo/PDSS_IdealGas.cpp
+++ b/src/thermo/PDSS_IdealGas.cpp
@@ -85,7 +85,7 @@ void PDSS_IdealGas::constructPDSSFile(VPStandardStateTP* tp, size_t spindex,
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    ifstream fin(path.c_str());
+    ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_IdealGas::constructPDSSFile","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PDSS_IonsFromNeutral.cpp b/src/thermo/PDSS_IonsFromNeutral.cpp
index 23691b516..c1d8ca973 100644
--- a/src/thermo/PDSS_IonsFromNeutral.cpp
+++ b/src/thermo/PDSS_IonsFromNeutral.cpp
@@ -173,7 +173,7 @@ void PDSS_IonsFromNeutral::constructPDSSFile(VPStandardStateTP* tp, size_t spind
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    ifstream fin(path.c_str());
+    ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_IonsFromNeutral::constructPDSSFile","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PDSS_SSVol.cpp b/src/thermo/PDSS_SSVol.cpp
index 6cf0892d5..2ec9650cd 100644
--- a/src/thermo/PDSS_SSVol.cpp
+++ b/src/thermo/PDSS_SSVol.cpp
@@ -132,7 +132,7 @@ void PDSS_SSVol::constructPDSSFile(VPStandardStateTP* tp, size_t spindex,
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    ifstream fin(path.c_str());
+    ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_SSVol::initThermo","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PDSS_Water.cpp b/src/thermo/PDSS_Water.cpp
index f481030de..f9124118c 100644
--- a/src/thermo/PDSS_Water.cpp
+++ b/src/thermo/PDSS_Water.cpp
@@ -149,7 +149,7 @@ void PDSS_Water::constructPDSSFile(VPStandardStateTP* tp, int spindex,
                            "input file is null");
     }
     std::string path = findInputFile(inputFile);
-    std::ifstream fin(path.c_str());
+    std::ifstream fin(path);
     if (!fin) {
         throw CanteraError("PDSS_Water::initThermo","could not open "
                            +path+" for reading.");
diff --git a/src/thermo/PureFluidPhase.cpp b/src/thermo/PureFluidPhase.cpp
index 9ed04c0b3..8169ba491 100644
--- a/src/thermo/PureFluidPhase.cpp
+++ b/src/thermo/PureFluidPhase.cpp
@@ -354,7 +354,7 @@ std::string PureFluidPhase::report(bool show_thermo, doublereal threshold) const
 {
     fmt::MemoryWriter b;
     if (name() != "") {
-        b.write("\n  {}:\n", name().c_str());
+        b.write("\n  {}:\n", name());
     }
     b.write("\n");
     b.write("       temperature    {:12.6g}  K\n", temperature());
diff --git a/src/transport/TransportFactory.cpp b/src/transport/TransportFactory.cpp
index 304073238..e7778c9f7 100644
--- a/src/transport/TransportFactory.cpp
+++ b/src/transport/TransportFactory.cpp
@@ -408,7 +408,7 @@ void TransportFactory::getLiquidSpeciesTransportData(const std::vector<const XML
                             size_t loc = specName.find(":");
                             std::string firstSpec = specName.substr(0,loc);
                             std::string secondSpec = specName.substr(loc+1);
-                            size_t index = temp_thermo->speciesIndex(firstSpec.c_str())+nsp*temp_thermo->speciesIndex(secondSpec.c_str());
+                            size_t index = temp_thermo->speciesIndex(firstSpec)+nsp*temp_thermo->speciesIndex(secondSpec);
                             data.mobilityRatio[index] = newLTP(propSpecNode, name, m_tranPropMap[nodeName], temp_thermo);
                         };
                     };
@@ -417,7 +417,7 @@ void TransportFactory::getLiquidSpeciesTransportData(const std::vector<const XML
                         for (size_t iSpec = 0; iSpec< nsp; iSpec++) {
                             XML_Node& propSpecNode = xmlChild.child(iSpec);
                             std::string specName = propSpecNode.name();
-                            size_t index = temp_thermo->speciesIndex(specName.c_str());
+                            size_t index = temp_thermo->speciesIndex(specName);
                             data.selfDiffusion[index] = newLTP(propSpecNode, name, m_tranPropMap[nodeName], temp_thermo);
                         };
                     };
@@ -533,7 +533,7 @@ void TransportFactory::getLiquidInteractionsTransportData(const XML_Node& transp
                             size_t loc = specName.find(":");
                             string firstSpec = specName.substr(0,loc);
                             string secondSpec = specName.substr(loc+1);
-                            size_t index = temp_thermo->speciesIndex(firstSpec.c_str())+nsp*temp_thermo->speciesIndex(secondSpec.c_str());
+                            size_t index = temp_thermo->speciesIndex(firstSpec)+nsp*temp_thermo->speciesIndex(secondSpec);
                             trParam.mobilityRatio[index] = newLTI(propSpecNode,
                                                                   m_tranPropMap[nodeName],
                                                                   trParam);
@@ -544,7 +544,7 @@ void TransportFactory::getLiquidInteractionsTransportData(const XML_Node& transp
                         for (size_t iSpec = 0; iSpec< nsp; iSpec++) {
                             XML_Node& propSpecNode = compDepNode.child(iSpec);
                             string specName = propSpecNode.name();
-                            size_t index = temp_thermo->speciesIndex(specName.c_str());
+                            size_t index = temp_thermo->speciesIndex(specName);
                             trParam.selfDiffusion[index] = newLTI(propSpecNode,
                                                                   m_tranPropMap[nodeName],
                                                                   trParam);
diff --git a/test/thermo/MaskellSolidSolnPhase_Test.cpp b/test/thermo/MaskellSolidSolnPhase_Test.cpp
index f75046d1e..f46426df8 100644
--- a/test/thermo/MaskellSolidSolnPhase_Test.cpp
+++ b/test/thermo/MaskellSolidSolnPhase_Test.cpp
@@ -18,7 +18,7 @@ public:
 
     void initializeTestPhaseWithXML(const std::string & filename)
     {
-        test_phase = newPhase(filename.c_str());
+        test_phase = newPhase(filename);
     }
 
     void set_r(const double r) {
diff --git a/test/thermo/phaseConstructors.cpp b/test/thermo/phaseConstructors.cpp
index 1c54a0044..53b3a1a7a 100644
--- a/test/thermo/phaseConstructors.cpp
+++ b/test/thermo/phaseConstructors.cpp
@@ -75,8 +75,8 @@ class ChemkinConversionTest : public testing::Test {
 public:
     void copyInputFile(const std::string& name) {
         std::string in_name = "../data/" + name;
-        std::ifstream source(in_name.c_str(), std::ios::binary);
-        std::ofstream dest(name.c_str(), std::ios::binary);
+        std::ifstream source(in_name, std::ios::binary);
+        std::ofstream dest(name, std::ios::binary);
         dest << source.rdbuf();
     }
 };
diff --git a/test_problems/shared/fileLog.h b/test_problems/shared/fileLog.h
index fda515d2f..bb9e2882c 100644
--- a/test_problems/shared/fileLog.h
+++ b/test_problems/shared/fileLog.h
@@ -7,7 +7,7 @@ class fileLog: public Cantera::Logger
 public:
     explicit fileLog(const std::string& fName) {
         m_fName = fName;
-        m_fs.open(fName.c_str(), std::ios::out);
+        m_fs.open(fName, std::ios::out);
     }
 
     virtual void write(const std::string& msg) {
diff --git a/test_problems/surfSolverTest/surfaceSolver2.cpp b/test_problems/surfSolverTest/surfaceSolver2.cpp
index 5cce74a54..08f3e2eb1 100644
--- a/test_problems/surfSolverTest/surfaceSolver2.cpp
+++ b/test_problems/surfSolverTest/surfaceSolver2.cpp
@@ -113,7 +113,6 @@ void printSurf(ostream& oooo, ThermoPhase* surfPhaseTP,
                InterfaceKinetics* iKin_ptr, double* src)
 {
     double x[MSSIZE];
-    char buf[256];
     oooo.precision(3);
     string surfParticlePhaseName = surfPhaseTP->id();
     surfPhaseTP->getMoleFractions(x);