diff --git a/include/cantera/thermo/HMWSoln.h b/include/cantera/thermo/HMWSoln.h
index 85cef0238..4cda78f78 100644
--- a/include/cantera/thermo/HMWSoln.h
+++ b/include/cantera/thermo/HMWSoln.h
@@ -1608,12 +1608,6 @@ public:
     virtual double d2A_DebyedT2_TP(double temperature = -1.0,
                                    double pressure = -1.0) const;
 
-    //! Reports the ionic radius of the kth species
-    /*!
-     *  @param k Species index
-     */
-    double AionicRadius(int k = 0) const;
-
     //! Print out all of the input Pitzer coefficients.
     void printCoeffs() const;
 
@@ -1698,9 +1692,6 @@ private:
      */
     int m_formPitzerTemp;
 
-    //! a_k = Size of the ionic species in the DH formulation. units = meters
-    vector_fp m_Aionic;
-
     //! Current value of the ionic strength on the molality scale Associated
     //! Salts, if present in the mechanism, don't contribute to the value of the
     //! ionic strength in this version of the Ionic strength.
diff --git a/src/thermo/HMWSoln.cpp b/src/thermo/HMWSoln.cpp
index 9bb175346..ea444e41a 100644
--- a/src/thermo/HMWSoln.cpp
+++ b/src/thermo/HMWSoln.cpp
@@ -581,17 +581,11 @@ double HMWSoln::d2A_DebyedT2_TP(double tempArg, double presArg) const
 
 // ---------- Other Property Functions
 
-double HMWSoln::AionicRadius(int k) const
-{
-    return m_Aionic[k];
-}
-
 // ------------ Private and Restricted Functions ------------------
 
 void HMWSoln::initLengths()
 {
     m_speciesSize.resize(m_kk);
-    m_Aionic.resize(m_kk, 0.0);
     m_tmpV.resize(m_kk, 0.0);
     m_molalitiesCropped.resize(m_kk, 0.0);
 
diff --git a/src/thermo/HMWSoln_input.cpp b/src/thermo/HMWSoln_input.cpp
index 6ee874393..2b816c5e4 100644
--- a/src/thermo/HMWSoln_input.cpp
+++ b/src/thermo/HMWSoln_input.cpp
@@ -1038,24 +1038,6 @@ void HMWSoln::initThermoXML(XML_Node& phaseNode, const std::string& id_)
             m_maxIionicStrength = getFloat(acNode, "maxIonicStrength");
         }
 
-        // Look for parameters for the Ionic radius
-        if (acNode.hasChild("ionicRadius")) {
-            XML_Node& irNode = acNode.child("ionicRadius");
-            double Afactor = 1.0;
-            if (irNode.hasAttrib("units")) {
-                string Aunits = irNode.attrib("units");
-                Afactor = toSI(Aunits);
-            }
-
-            if (irNode.hasAttrib("default")) {
-                string ads = irNode.attrib("default");
-                double ad = fpValue(ads);
-                for (size_t k = 0; k < m_kk; k++) {
-                    m_Aionic[k] = ad * Afactor;
-                }
-            }
-        }
-
         // Loop through the children getting multiple instances of parameters
         if (acNodePtr) {
             for (size_t i = 0; i < acNodePtr->nChildren(); i++) {
diff --git a/test_problems/cathermo/HMW_test_1/HMW_test_1.cpp b/test_problems/cathermo/HMW_test_1/HMW_test_1.cpp
index bafdabaae..b4e0c828c 100644
--- a/test_problems/cathermo/HMW_test_1/HMW_test_1.cpp
+++ b/test_problems/cathermo/HMW_test_1/HMW_test_1.cpp
@@ -42,10 +42,6 @@ int main(int argc, char** argv)
 
         size_t nsp = HMW->nSpecies();
 
-        double a1 = HMW->AionicRadius(1);
-        printf("a1 = %g\n", a1);
-        double a2 = HMW->AionicRadius(2);
-        printf("a2 = %g\n", a2);
         double mu0[100];
         double moll[100];
         string sName;
diff --git a/test_problems/cathermo/HMW_test_1/output_noD_blessed.txt b/test_problems/cathermo/HMW_test_1/output_noD_blessed.txt
index 879760ab0..eeccb9de8 100644
--- a/test_problems/cathermo/HMW_test_1/output_noD_blessed.txt
+++ b/test_problems/cathermo/HMW_test_1/output_noD_blessed.txt
@@ -26,8 +26,6 @@ Index  Name                  MoleF   MolalityCropped  Charge
  Na+              OH-              Cl-               -0.00600 
  OH-              Cl-              Na+               -0.00600 
  OH-              Na+              Cl-               -0.00600 
-a1 = 3.04284e-10
-a2 = 3.04284e-10
             Name      Activity  ActCoeffMolal    MoleFract      Molality
           H2O(L)        0.7546        0.9204        0.8198       55.5084
              Cl-        6.0958        0.9994        0.0901        6.0997
diff --git a/test_problems/cathermo/HMW_test_3/HMW_test_3.cpp b/test_problems/cathermo/HMW_test_3/HMW_test_3.cpp
index 1229b2c38..f4d166108 100644
--- a/test_problems/cathermo/HMW_test_3/HMW_test_3.cpp
+++ b/test_problems/cathermo/HMW_test_3/HMW_test_3.cpp
@@ -41,10 +41,6 @@ int main(int argc, char** argv)
 
         size_t nsp = HMW->nSpecies();
 
-        double a1 = HMW->AionicRadius(1);
-        printf("a1 = %.4f\n", a1);
-        double a2 = HMW->AionicRadius(2);
-        printf("a2 = %.4f\n", a2);
         double mu0[100];
         double moll[100];
         string sName;
diff --git a/test_problems/cathermo/HMW_test_3/output_noD_blessed.txt b/test_problems/cathermo/HMW_test_3/output_noD_blessed.txt
index 1c8217aa3..c5088cf09 100644
--- a/test_problems/cathermo/HMW_test_3/output_noD_blessed.txt
+++ b/test_problems/cathermo/HMW_test_3/output_noD_blessed.txt
@@ -1,5 +1,3 @@
-a1 = 0.0000
-a2 = 0.0000
        Temperature = 423.1500 K
 Index  Name                  MoleF   MolalityCropped  Charge
  0     H2O(L)            8.1982292e-01  5.5508435e+01   0.0