Forgot the member function getCp_R_ref() in the previous commit.

This commit adds that function.

Cantera/src/thermo/SingleSpeciesTP.cpp

@@ -331,6 +331,16 @@ namespace Cantera {
       er[0] = m_s0_R[0];
     }
 
+  /**
+     * Get the nondimensional Gibbs functions for the standard
+     * state of the species at the current T and reference pressure
+     * for the species.
+     */
+    void SingleSpeciesTP::getCp_R_ref(doublereal* cpr) const {
+	_updateThermo();
+	cpr[0] = m_cp0_R[0];
+    }
+
 
     /*
      * ------------------ Setting the State ------------------------