diff --git a/include/cantera/thermo/PDSS.h b/include/cantera/thermo/PDSS.h
index 4b7509f72..99e0b3f69 100644
--- a/include/cantera/thermo/PDSS.h
+++ b/include/cantera/thermo/PDSS.h
@@ -128,6 +128,7 @@ namespace Cantera
 
 class XML_Node;
 class MultiSpeciesThermo;
+class SpeciesThermoInterpType;
 class VPStandardStateTP;
 
 //! Virtual base class for a species with a pressure dependent standard state
@@ -168,19 +169,9 @@ public:
     //! @name Constructors
     //! @{
 
-    //! Empty Constructor
+    //! Default Constructor
     PDSS();
 
-    //! Constructor that initializes the object by examining the XML entries
-    //! from the ThermoPhase object
-    /*!
-     * This function calls the constructPDSS member function.
-     *
-     * @param tp       Pointer to the ThermoPhase object pertaining to the phase
-     * @param spindex  Species index of the species in the phase
-     */
-    PDSS(VPStandardStateTP* tp, size_t spindex);
-
     // PDSS objects are not copyable or assignable
     PDSS(const PDSS& b) = delete;
     PDSS& operator=(const PDSS& b) = delete;
@@ -433,35 +424,45 @@ public:
     //! @name Initialization of the Object
     //! @{
 
-    //! Initialization routine for all of the shallow pointers
-    /*!
-     * This is a cascading call, where each level should call the the parent
-     * level.
-     *
-     * The initThermo() routines get called before the initThermoXML() routines
-     * from the constructPDSSXML() routine.
-     *
-     * Calls initPtrs();
-     */
-    virtual void initThermo();
+    //! Set the SpeciesThermoInterpType object used to calculate reference
+    //! state properties
+    void setReferenceThermo(shared_ptr<SpeciesThermoInterpType> stit) {
+        m_spthermo = stit;
+    }
 
-    //! Initialization routine for the PDSS object based on the phaseNode
+    //! Returns 'true' if this object should be used in an STITbyPDSS object
+    //! in the phase's reference thermo manager, or 'false' if a separate
+    //! SpeciesThermoInterpType should be constructed
+    virtual bool useSTITbyPDSS() const {
+        return false;
+    }
+
+    //! Set the parent VPStandardStateTP object of this PDSS object
+    /*!
+     * This information is only used by certain PDSS subclasses
+     * @param phase   Pointer to the parent phase
+     * @param k       Index of this species in the phase
+     */
+    virtual void setParent(VPStandardStateTP* phase, size_t k) {}
+
+    //! Initialization routine
     /*!
      * This is a cascading call, where each level should call the the parent
      * level.
-     *
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param id         Optional parameter identifying the name of the phase.
-     *                   If none is given, the first XML phase element will be
-     *                   used.
      */
-    virtual void initThermoXML(const XML_Node& phaseNode, const std::string& id);
+    virtual void initThermo() {}
+
+    //! Initialization routine for the PDSS object based on the speciesNode
+    /*!
+     * This is a cascading call, where each level should call the the parent
+     * level. This function is called before initThermo()
+     */
+    virtual void setParametersFromXML(const XML_Node& speciesNode) {}
 
     //! This utility function reports back the type of parameterization and
     //! all of the parameters for the species, index.
     /*!
-     * @param kindex     Species index
+     * @param kindex    Species index (unused)
      * @param type      Integer type of the standard type (unused)
      * @param c         Vector of coefficients used to set the
      *                  parameters for the standard state.
@@ -491,28 +492,12 @@ protected:
     //! Maximum temperature
     doublereal m_maxTemp;
 
-    //! ThermoPhase which this species belongs to.
-    /*!
-     * Note, in some applications (i.e., mostly testing applications, this may
-     * be a null value. Applications should test whether this is null before
-     * usage.
-     */
-    VPStandardStateTP* m_tp;
-
     //! Molecular Weight of the species
     doublereal m_mw;
 
-    //! Species index in the ThermoPhase corresponding to this species.
-    size_t m_spindex;
-
-    //! Pointer to the species thermodynamic property manager.
-    /*!
-     * This is a copy of the pointer in the ThermoPhase object. Note, this
-     * object doesn't own the pointer. If the MultiSpeciesThermo object
-     * doesn't know or doesn't control the calculation, this will be set to
-     * zero.
-     */
-    MultiSpeciesThermo* m_spthermo;
+    //! Pointer to the species thermodynamic property manager. Not used in all
+    //! PDSS models.
+    shared_ptr<SpeciesThermoInterpType> m_spthermo;
 };
 
 //! Base class for PDSS classes which compute molar properties directly
diff --git a/include/cantera/thermo/PDSS_ConstVol.h b/include/cantera/thermo/PDSS_ConstVol.h
index cce3dd393..745e853db 100644
--- a/include/cantera/thermo/PDSS_ConstVol.h
+++ b/include/cantera/thermo/PDSS_ConstVol.h
@@ -22,32 +22,9 @@ namespace Cantera
 class PDSS_ConstVol : public PDSS_Nondimensional
 {
 public:
-    //! @name  Constructors
-    //! @{
+    //! Default Constructor
+    PDSS_ConstVol();
 
-    //! Constructor
-    /*!
-     *  @param tp       Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex  Species index of the species in the phase
-     */
-    PDSS_ConstVol(VPStandardStateTP* tp, size_t spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSSXML member function.
-     *
-     *  @param vptp_ptr    Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex     Species index of the species in the phase
-     *  @param speciesNode Reference to the species XML tree.
-     *  @param phaseRef    Reference to the XML tree containing the phase information.
-     *  @param spInstalled Boolean indicating whether the species is installed
-     *                     yet or not.
-     */
-    PDSS_ConstVol(VPStandardStateTP* vptp_ptr, size_t spindex, const XML_Node& speciesNode,
-                  const XML_Node& phaseRef, bool spInstalled);
-
-    //! @}
     //! @name Molar Thermodynamic Properties of the Species Standard State in
     //!     the Solution
     //! @{
@@ -76,29 +53,7 @@ public:
     //! @{
 
     virtual void initThermo();
-
-    //!  Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the object.
-     *
-     *   basic logic:
-     *     - initThermo()                 (cascade)
-     *     - getStuff from species Part of XML file
-     *     - initThermoXML(phaseNode)      (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param speciesNode XML Node containing the species information
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param spInstalled  Boolean indicating whether the species is
-     *                     already installed.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, size_t spindex,
-                          const XML_Node& speciesNode,
-                          const XML_Node& phaseNode, bool spInstalled);
-
-    virtual void initThermoXML(const XML_Node& phaseNode, const std::string& id);
+    virtual void setParametersFromXML(const XML_Node& speciesNode);
 
     //@}
 
diff --git a/include/cantera/thermo/PDSS_HKFT.h b/include/cantera/thermo/PDSS_HKFT.h
index 0ba8c5f68..6f8114cc6 100644
--- a/include/cantera/thermo/PDSS_HKFT.h
+++ b/include/cantera/thermo/PDSS_HKFT.h
@@ -27,37 +27,9 @@ class WaterProps;
 class PDSS_HKFT : public PDSS_Molar
 {
 public:
-    //! @name  Constructors
-    //! @{
+    //! Default Constructor
+    PDSS_HKFT();
 
-    //! Constructor that initializes the object by examining the XML entries
-    //! from the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSS member function.
-     *
-     *  @param tp        Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex   Species index of the species in the phase
-     */
-    PDSS_HKFT(VPStandardStateTP* tp, size_t spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSSXML member function.
-     *
-     *  @param vptp_ptr    Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex     Species index of the species in the phase
-     *  @param speciesNode Reference to the species XML tree.
-     *  @param phaseRef    Reference to the XML tree containing the phase information.
-     *  @param spInstalled Boolean indicating whether the species is installed yet
-     *                     or not.
-     */
-    PDSS_HKFT(VPStandardStateTP* vptp_ptr, size_t spindex, const XML_Node& speciesNode,
-              const XML_Node& phaseRef, bool spInstalled);
-
-    virtual ~PDSS_HKFT();
-
-    //! @}
     //! @name  Molar Thermodynamic Properties of the Solution
     //! @{
 
@@ -107,28 +79,15 @@ public:
     //! @name Initialization of the Object
     //! @{
 
+    void setParent(VPStandardStateTP* phase, size_t k) {
+        m_tp = phase;
+        m_spindex = k;
+    }
+
+    virtual bool useSTITbyPDSS() const { return true; }
     virtual void initThermo();
 
-    //! Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the object.
-     *
-     *   basic logic:
-     *     - initThermo()                 (cascade)
-     *     - getStuff from species Part of XML file
-     *     - initThermoXML(phaseNode)      (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param speciesNode XML Node containing the species information
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param spInstalled  Boolean indicating whether the species is
-     *                     already installed.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, size_t spindex,
-                          const XML_Node& speciesNode,
-                          const XML_Node& phaseNode, bool spInstalled);
+    void setParametersFromXML(const XML_Node& speciesNode);
 
     //! This utility function reports back the type of parameterization and
     //! all of the parameters for the species, index.
@@ -162,6 +121,9 @@ public:
     //@}
 
 private:
+    VPStandardStateTP* m_tp; //!< Parent VPStandardStateTP (ThermoPhase) object
+    size_t m_spindex; //!< Index of this species within the parent phase
+
     //! Main routine that actually calculates the Gibbs free energy difference
     //! between the reference state at Tr, Pr and T,P
     /*!
diff --git a/include/cantera/thermo/PDSS_IdealGas.h b/include/cantera/thermo/PDSS_IdealGas.h
index e8e6d98a0..a6d84a45c 100644
--- a/include/cantera/thermo/PDSS_IdealGas.h
+++ b/include/cantera/thermo/PDSS_IdealGas.h
@@ -24,32 +24,9 @@ namespace Cantera
 class PDSS_IdealGas : public PDSS_Nondimensional
 {
 public:
-    //! @name  Constructors
-    //! @{
+    //! Default Constructor
+    PDSS_IdealGas();
 
-    //! Constructor
-    /*!
-     *  @param tp        Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex   Species index of the species in the phase
-     */
-    PDSS_IdealGas(VPStandardStateTP* tp, int spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSSXML member function.
-     *
-     *  @param vptp_ptr    Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex     Species index of the species in the phase
-     *  @param speciesNode Reference to the species XML tree.
-     *  @param phaseRef    Reference to the XML tree containing the phase information.
-     *  @param spInstalled Boolean indicating whether the species is installed yet
-     *                     or not.
-     */
-    PDSS_IdealGas(VPStandardStateTP* vptp_ptr, size_t spindex, const XML_Node& speciesNode,
-                  const XML_Node& phaseRef, bool spInstalled);
-
-    //! @}
     //! @name Molar Thermodynamic Properties of the Species Standard State in the Solution
     //! @{
 
@@ -72,26 +49,6 @@ public:
     //! @name Initialization of the Object
     //! @{
 
-    //!Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the object.
-     *
-     * basic logic:
-     *   - initThermo()                 (cascade)
-     *   - get stuff from species part of XML file
-     *   - initThermoXML(phaseNode)     (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param id         Optional parameter identifying the name of the
-     *                   phase. If none is given, the first XML
-     *                   phase element will be used.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, size_t spindex,
-                          const XML_Node& phaseNode, const std::string& id);
-
     virtual void initThermo();
     //@}
 };
diff --git a/include/cantera/thermo/PDSS_IonsFromNeutral.h b/include/cantera/thermo/PDSS_IonsFromNeutral.h
index 52dd6ec51..aca44108b 100644
--- a/include/cantera/thermo/PDSS_IonsFromNeutral.h
+++ b/include/cantera/thermo/PDSS_IonsFromNeutral.h
@@ -35,32 +35,9 @@ class ThermoPhase;
 class PDSS_IonsFromNeutral : public PDSS_Nondimensional
 {
 public:
-    //! @name  Constructors
-    //! @{
+    //! Default constructor
+    PDSS_IonsFromNeutral();
 
-    //! Constructor
-    /*!
-     * @param tp       Pointer to the ThermoPhase object pertaining to the phase
-     * @param spindex  Species index of the species in the phase
-     */
-    PDSS_IonsFromNeutral(VPStandardStateTP* tp, size_t spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the ThermoPhase object
-    /*!
-     * This function calls the constructPDSSXML member function.
-     *
-     * @param vptp_ptr    Pointer to the ThermoPhase object pertaining to the phase
-     * @param spindex     Species index of the species in the phase
-     * @param speciesNode Reference to the species XML tree.
-     * @param phaseRef    Reference to the XML tree containing the phase information.
-     * @param spInstalled Boolean indicating whether the species is installed
-     *                    yet or not.
-     */
-    PDSS_IonsFromNeutral(VPStandardStateTP* vptp_ptr, size_t spindex, const XML_Node& speciesNode,
-                         const XML_Node& phaseRef, bool spInstalled);
-
-    //! @}
     //! @name  Molar Thermodynamic Properties of the Species Standard State in the Solution
     //! @{
 
@@ -109,29 +86,11 @@ public:
     //! @name Initialization of the Object
     //! @{
 
-    //! Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the object.
-     *
-     *   basic logic:
-     *     - initThermo()                 (cascade)
-     *     - getStuff from species Part of XML file
-     *     - initThermoXML(phaseNode)      (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param speciesNode  Reference to the phase Information for the species
-     *                     that this standard state refers to
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param id         Optional parameter identifying the name of the
-     *                   phase. If none is given, the first XML
-     *                   phase element will be used.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, size_t spindex,
-                          const XML_Node& speciesNode,
-                          const XML_Node& phaseNode, const std::string& id);
+    void setParent(VPStandardStateTP* phase, size_t k);
 
+    virtual bool useSTITbyPDSS() const { return true; }
+
+    void setParametersFromXML(const XML_Node& speciesNode);
     virtual void initThermo();
     //@}
 
@@ -142,6 +101,8 @@ protected:
      */
     const ThermoPhase* neutralMoleculePhase_;
 
+    std::map<std::string, double> neutralSpeciesMultipliers_;
+
 public:
     //! Number of neutral molecule species that make up the stoichiometric
     //! vector for this species, in terms of calculating thermodynamic functions
diff --git a/include/cantera/thermo/PDSS_SSVol.h b/include/cantera/thermo/PDSS_SSVol.h
index 354eeda10..adc7625f9 100644
--- a/include/cantera/thermo/PDSS_SSVol.h
+++ b/include/cantera/thermo/PDSS_SSVol.h
@@ -163,32 +163,9 @@ namespace Cantera
 class PDSS_SSVol : public PDSS_Nondimensional
 {
 public:
-    //! @name  Constructors
-    //! @{
+    //! Default Constructor
+    PDSS_SSVol();
 
-    //! Constructor
-    /*!
-     *  @param tp        Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex   Species index of the species in the phase
-     */
-    PDSS_SSVol(VPStandardStateTP* tp, size_t spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSSXML member function.
-     *
-     *  @param vptp_ptr    Pointer to the ThermoPhase object pertaining to the phase
-     *  @param spindex     Species index of the species in the phase
-     *  @param speciesNode Reference to the species XML tree.
-     *  @param phaseRef    Reference to the XML tree containing the phase information.
-     *  @param spInstalled Boolean indicating whether the species is installed yet
-     *                     or not.
-     */
-    PDSS_SSVol(VPStandardStateTP* vptp_ptr, size_t spindex, const XML_Node& speciesNode,
-               const XML_Node& phaseRef, bool spInstalled);
-
-    //! @}
     //! @name  Molar Thermodynamic Properties of the Species Standard State in the Solution
     //! @{
 
@@ -222,29 +199,7 @@ private:
     //! @{
 
     virtual void initThermo();
-
-    //!  Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the object.
-     *
-     *   basic logic:
-     *     - initThermo()                 (cascade)
-     *     - getStuff from species Part of XML file
-     *     - initThermoXML(phaseNode)      (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param speciesNode XML Node containing the species information
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param spInstalled  Boolean indicating whether the species is
-     *                     already installed.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, size_t spindex,
-                          const XML_Node& speciesNode,
-                          const XML_Node& phaseNode, bool spInstalled);
-
-    virtual void initThermoXML(const XML_Node& phaseNode, const std::string& id);
+    virtual void setParametersFromXML(const XML_Node& speciesNode);
     //@}
 
 private:
diff --git a/include/cantera/thermo/PDSS_Water.h b/include/cantera/thermo/PDSS_Water.h
index 92a81a09c..9c79f04b0 100644
--- a/include/cantera/thermo/PDSS_Water.h
+++ b/include/cantera/thermo/PDSS_Water.h
@@ -49,40 +49,9 @@ namespace Cantera
 class PDSS_Water : public PDSS_Molar
 {
 public:
-    //! @name  Constructors
-    //! @{
-
-    //! Bare constructor
-    /*!
-     *  eliminate?
-     */
+    //! Default constructor
     PDSS_Water();
 
-    //! Constructor that initializes the object by examining the XML entries
-    //! from the ThermoPhase object
-    /*!
-     *  This function calls the constructPDSS member function.
-     *
-     * @param tp       Pointer to the ThermoPhase object pertaining to the phase
-     * @param spindex  Species index of the species in the phase
-     */
-    PDSS_Water(VPStandardStateTP* tp, int spindex);
-
-    //! Constructor that initializes the object by examining the input file
-    //! of the variable pressure ThermoPhase object
-    /*!
-     * This function calls the constructPDSSXML member function.
-     *
-     * @param tp        Pointer to the ThermoPhase object pertaining to the phase
-     * @param spindex   Species index of the species in the phase
-     * @param speciesNode Reference to the species XML tree.
-     * @param phaseRef  Reference to the XML tree containing the phase information.
-     * @param spInstalled Is the species already installed.
-     */
-    PDSS_Water(VPStandardStateTP* tp, int spindex, const XML_Node& speciesNode,
-               const XML_Node& phaseRef, bool spInstalled);
-
-    //! @}
     //! @name  Molar Thermodynamic Properties of the Species Standard State in the Solution
     //! @{
 
@@ -180,33 +149,8 @@ public:
     }
 
     //! @}
-    //! @name Initialization of the Object
-    //! @{
 
-    //! Internal routine that initializes the underlying water model
-    void constructSet();
-
-    //!Initialization of a PDSS object using an XML tree
-    /*!
-     * This routine is a driver for the initialization of the
-     * object.
-     *
-     *   basic logic:
-     *     - initThermo()                 (cascade)
-     *     - getStuff from species Part of XML file
-     *     - initThermoXML(phaseNode)      (cascade)
-     *
-     * @param vptp_ptr   Pointer to the Variable pressure ThermoPhase object
-     * @param spindex    Species index within the phase
-     * @param phaseNode  Reference to the phase Information for the phase
-     *                   that owns this species.
-     * @param id         Optional parameter identifying the name of the
-     *                   phase. If none is given, the first XML
-     *                   phase element will be used.
-     */
-    void constructPDSSXML(VPStandardStateTP* vptp_ptr, int spindex,
-                          const XML_Node& phaseNode, const std::string& id);
-    //@}
+    virtual bool useSTITbyPDSS() const { return true; }
 
 private:
     //! Pointer to the WaterPropsIAPWS object, which does the actual calculations
@@ -259,9 +203,6 @@ private:
      */
     doublereal SW_Offset;
 
-    //! Verbose flag - used?
-    bool m_verbose;
-
 public:
     /**
      *  Since this phase represents a liquid phase, it's an error to
diff --git a/include/cantera/thermo/VPStandardStateTP.h b/include/cantera/thermo/VPStandardStateTP.h
index 985e17290..3828fac3d 100644
--- a/include/cantera/thermo/VPStandardStateTP.h
+++ b/include/cantera/thermo/VPStandardStateTP.h
@@ -243,7 +243,6 @@ public:
     //@{
 
     virtual void initThermo();
-    virtual void initThermoXML(XML_Node& phaseNode, const std::string& id);
 
     using Phase::addSpecies;
     virtual bool addSpecies(shared_ptr<Species> spec);
diff --git a/src/thermo/PDSS.cpp b/src/thermo/PDSS.cpp
index f077c76b9..3ef9a0dce 100644
--- a/src/thermo/PDSS.cpp
+++ b/src/thermo/PDSS.cpp
@@ -20,40 +20,10 @@ PDSS::PDSS() :
     m_p0(-1.0),
     m_minTemp(-1.0),
     m_maxTemp(10000.0),
-    m_tp(0),
-    m_mw(0.0),
-    m_spindex(npos),
-    m_spthermo(0)
+    m_mw(0.0)
 {
 }
 
-PDSS::PDSS(VPStandardStateTP* tp, size_t spindex) :
-    m_temp(-1.0),
-    m_pres(-1.0),
-    m_p0(-1.0),
-    m_minTemp(-1.0),
-    m_maxTemp(10000.0),
-    m_tp(tp),
-    m_mw(0.0),
-    m_spindex(spindex),
-    m_spthermo(0)
-{
-    if (tp) {
-        m_spthermo = &tp->speciesThermo();
-    }
-}
-
-void PDSS::initThermoXML(const XML_Node& phaseNode, const std::string& id)
-{
-    AssertThrow(m_tp != 0, "PDSS::initThermoXML()");
-}
-
-void PDSS::initThermo()
-{
-    AssertThrow(m_tp != 0, "PDSS::initThermo()");
-    m_mw = m_tp->molecularWeight(m_spindex);
-}
-
 doublereal PDSS::enthalpy_mole() const
 {
     throw NotImplementedError("PDSS::enthalpy_mole()");
@@ -229,7 +199,7 @@ void PDSS::reportParams(size_t& kindex, int& type,
                         doublereal& maxTemp_,
                         doublereal& refPressure_) const
 {
-    kindex = m_spindex;
+    kindex = npos;
     type = 0;
     minTemp_ = m_minTemp;
     maxTemp_ = m_maxTemp;
diff --git a/src/thermo/PDSS_ConstVol.cpp b/src/thermo/PDSS_ConstVol.cpp
index ccaf0fb6e..dbfdc7d32 100644
--- a/src/thermo/PDSS_ConstVol.cpp
+++ b/src/thermo/PDSS_ConstVol.cpp
@@ -15,30 +15,14 @@ using namespace std;
 
 namespace Cantera
 {
-PDSS_ConstVol::PDSS_ConstVol(VPStandardStateTP* tp, size_t spindex) :
-    PDSS(tp, spindex)
+
+PDSS_ConstVol::PDSS_ConstVol()
 {
 }
 
-PDSS_ConstVol::PDSS_ConstVol(VPStandardStateTP* tp, size_t spindex,
-                             const XML_Node& speciesNode,
-                             const XML_Node& phaseRoot,
-                             bool spInstalled) :
-    PDSS(tp, spindex)
+void PDSS_ConstVol::setParametersFromXML(const XML_Node& speciesNode)
 {
-    constructPDSSXML(tp, spindex, speciesNode, phaseRoot, spInstalled);
-}
-
-void PDSS_ConstVol::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
-                                     const XML_Node& speciesNode,
-                                     const XML_Node& phaseNode, bool spInstalled)
-{
-    PDSS::initThermo();
-    m_p0 = m_tp->speciesThermo().refPressure(m_spindex);
-
-    if (!spInstalled) {
-        throw CanteraError("PDSS_ConstVol::constructPDSSXML", "spInstalled false not handled");
-    }
+    PDSS::setParametersFromXML(speciesNode);
 
     const XML_Node* ss = speciesNode.findByName("standardState");
     if (!ss) {
@@ -53,19 +37,12 @@ void PDSS_ConstVol::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
     m_constMolarVolume = getFloat(*ss, "molarVolume", "toSI");
 }
 
-void PDSS_ConstVol::initThermoXML(const XML_Node& phaseNode, const std::string& id)
-{
-    PDSS::initThermoXML(phaseNode, id);
-    m_minTemp = m_spthermo->minTemp(m_spindex);
-    m_maxTemp = m_spthermo->maxTemp(m_spindex);
-    m_p0 = m_spthermo->refPressure(m_spindex);
-    m_mw = m_tp->molecularWeight(m_spindex);
-}
-
 void PDSS_ConstVol::initThermo()
 {
     PDSS::initThermo();
-    m_p0 = m_tp->speciesThermo().refPressure(m_spindex);
+    m_minTemp = m_spthermo->minTemp();
+    m_maxTemp = m_spthermo->maxTemp();
+    m_p0 = m_spthermo->refPressure();
     m_V0 = m_constMolarVolume;
     m_Vss = m_constMolarVolume;
 }
@@ -92,7 +69,7 @@ void PDSS_ConstVol::setPressure(doublereal p)
 void PDSS_ConstVol::setTemperature(doublereal temp)
 {
     m_temp = temp;
-    m_spthermo->update_single(m_spindex, temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
+    m_spthermo->updatePropertiesTemp(temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
     m_g0_RT = m_h0_RT - m_s0_R;
 
     doublereal del_pRT = (m_pres - m_p0) / (GasConstant * m_temp);
diff --git a/src/thermo/PDSS_HKFT.cpp b/src/thermo/PDSS_HKFT.cpp
index 1780646e7..8c4d0fd74 100644
--- a/src/thermo/PDSS_HKFT.cpp
+++ b/src/thermo/PDSS_HKFT.cpp
@@ -22,69 +22,33 @@ namespace Cantera
 // Set the default to error exit if there is an input file inconsistency
 int PDSS_HKFT::s_InputInconsistencyErrorExit = 1;
 
-PDSS_HKFT::PDSS_HKFT(VPStandardStateTP* tp, size_t spindex) :
-    PDSS(tp, spindex),
-    m_waterSS(0),
-    m_densWaterSS(-1.0),
-    m_born_coeff_j(-1.0),
-    m_r_e_j(-1.0),
-    m_deltaG_formation_tr_pr(0.0),
-    m_deltaH_formation_tr_pr(0.0),
-    m_Mu0_tr_pr(0.0),
-    m_Entrop_tr_pr(0.0),
-    m_a1(0.0),
-    m_a2(0.0),
-    m_a3(0.0),
-    m_a4(0.0),
-    m_c1(0.0),
-    m_c2(0.0),
-    m_omega_pr_tr(0.0),
-    m_Y_pr_tr(0.0),
-    m_Z_pr_tr(0.0),
-    m_presR_bar(0.0),
-    m_domega_jdT_prtr(0.0),
-    m_charge_j(0.0)
+PDSS_HKFT::PDSS_HKFT()
+    : m_waterSS(0)
+    , m_densWaterSS(-1.0)
+    , m_born_coeff_j(-1.0)
+    , m_r_e_j(-1.0)
+    , m_deltaG_formation_tr_pr(0.0)
+    , m_deltaH_formation_tr_pr(0.0)
+    , m_Mu0_tr_pr(0.0)
+    , m_Entrop_tr_pr(0.0)
+    , m_a1(0.0)
+    , m_a2(0.0)
+    , m_a3(0.0)
+    , m_a4(0.0)
+    , m_c1(0.0)
+    , m_c2(0.0)
+    , m_omega_pr_tr(0.0)
+    , m_Y_pr_tr(0.0)
+    , m_Z_pr_tr(0.0)
+    , m_presR_bar(0.0)
+    , m_domega_jdT_prtr(0.0)
+    , m_charge_j(0.0)
 {
     m_pres = OneAtm;
     m_presR_bar = OneAtm * 1.0E-5;
     m_presR_bar = 1.0;
 }
 
-PDSS_HKFT::PDSS_HKFT(VPStandardStateTP* tp, size_t spindex, const XML_Node& speciesNode,
-                     const XML_Node& phaseRoot, bool spInstalled) :
-    PDSS(tp, spindex),
-    m_waterSS(0),
-    m_densWaterSS(-1.0),
-    m_born_coeff_j(-1.0),
-    m_r_e_j(-1.0),
-    m_deltaG_formation_tr_pr(0.0),
-    m_deltaH_formation_tr_pr(0.0),
-    m_Mu0_tr_pr(0.0),
-    m_Entrop_tr_pr(0.0),
-    m_a1(0.0),
-    m_a2(0.0),
-    m_a3(0.0),
-    m_a4(0.0),
-    m_c1(0.0),
-    m_c2(0.0),
-    m_omega_pr_tr(0.0),
-    m_Y_pr_tr(0.0),
-    m_Z_pr_tr(0.0),
-    m_presR_bar(0.0),
-    m_domega_jdT_prtr(0.0),
-    m_charge_j(0.0)
-{
-    m_pres = OneAtm;
-    m_presR_bar = OneAtm * 1.0E-5;
-    m_presR_bar = 1.0;
-    // We have to read the info from here
-    constructPDSSXML(tp, spindex, speciesNode, phaseRoot, spInstalled);
-}
-
-PDSS_HKFT::~PDSS_HKFT()
-{
-}
-
 doublereal PDSS_HKFT::enthalpy_mole() const
 {
     // Ok we may change this evaluation method in the future.
@@ -333,18 +297,13 @@ void PDSS_HKFT::initThermo()
     }
 }
 
-void PDSS_HKFT::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
-                                 const XML_Node& speciesNode,
-                                 const XML_Node& phaseNode, bool spInstalled)
+void PDSS_HKFT::setParametersFromXML(const XML_Node& speciesNode)
 {
+    PDSS::setParametersFromXML(speciesNode);
     int hasDGO = 0;
     int hasSO = 0;
     int hasDHO = 0;
 
-    if (!spInstalled) {
-        throw CanteraError("PDSS_HKFT::constructPDSSXML", "spInstalled false not handled");
-    }
-
     const XML_Node* tn = speciesNode.findByName("thermo");
     if (!tn) {
         throw CanteraError("PDSS_HKFT::constructPDSSXML",
diff --git a/src/thermo/PDSS_IdealGas.cpp b/src/thermo/PDSS_IdealGas.cpp
index 0311f8ffe..622b2e052 100644
--- a/src/thermo/PDSS_IdealGas.cpp
+++ b/src/thermo/PDSS_IdealGas.cpp
@@ -15,32 +15,17 @@ using namespace std;
 
 namespace Cantera
 {
-PDSS_IdealGas::PDSS_IdealGas(VPStandardStateTP* tp, int spindex) :
-    PDSS(tp, spindex)
-{
-}
 
-PDSS_IdealGas::PDSS_IdealGas(VPStandardStateTP* tp, size_t spindex, const XML_Node& speciesNode,
-                             const XML_Node& phaseRoot, bool spInstalled) :
-    PDSS(tp, spindex)
-{
-    if (!spInstalled) {
-        throw CanteraError("PDSS_IdealGas", "sp installing not done yet");
-    }
-    constructPDSSXML(tp, spindex, phaseRoot, "");
-}
-
-void PDSS_IdealGas::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
-                                     const XML_Node& phaseNode, const std::string& id)
+PDSS_IdealGas::PDSS_IdealGas()
 {
 }
 
 void PDSS_IdealGas::initThermo()
 {
     PDSS::initThermo();
-    m_p0 = m_tp->speciesThermo().refPressure(m_spindex);
-    m_minTemp = m_spthermo->minTemp(m_spindex);
-    m_maxTemp = m_spthermo->maxTemp(m_spindex);
+    m_p0 = m_spthermo->refPressure();
+    m_minTemp = m_spthermo->minTemp();
+    m_maxTemp = m_spthermo->maxTemp();
 }
 
 doublereal PDSS_IdealGas::intEnergy_mole() const
@@ -68,7 +53,7 @@ void PDSS_IdealGas::setPressure(doublereal p)
 void PDSS_IdealGas::setTemperature(doublereal temp)
 {
     m_temp = temp;
-    m_spthermo->update_single(m_spindex, temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
+    m_spthermo->updatePropertiesTemp(temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
     m_g0_RT = m_h0_RT - m_s0_R;
     m_V0 = GasConstant * m_temp / m_p0;
     m_hss_RT = m_h0_RT;
diff --git a/src/thermo/PDSS_IonsFromNeutral.cpp b/src/thermo/PDSS_IonsFromNeutral.cpp
index 71e369c87..46dcd39f8 100644
--- a/src/thermo/PDSS_IonsFromNeutral.cpp
+++ b/src/thermo/PDSS_IonsFromNeutral.cpp
@@ -16,34 +16,23 @@ using namespace std;
 
 namespace Cantera
 {
-PDSS_IonsFromNeutral::PDSS_IonsFromNeutral(VPStandardStateTP* tp, size_t spindex) :
-    PDSS(tp, spindex),
-    neutralMoleculePhase_(0),
-    numMult_(0),
-    add2RTln2_(true),
-    specialSpecies_(0)
+
+PDSS_IonsFromNeutral::PDSS_IonsFromNeutral()
+    : neutralMoleculePhase_(0)
+    , numMult_(0)
+    , add2RTln2_(true)
+    , specialSpecies_(0)
 {
 }
 
-PDSS_IonsFromNeutral::PDSS_IonsFromNeutral(VPStandardStateTP* tp, size_t spindex, const XML_Node& speciesNode,
-        const XML_Node& phaseRoot, bool spInstalled) :
-    PDSS(tp, spindex),
-    neutralMoleculePhase_(0),
-    numMult_(0),
-    add2RTln2_(true),
-    specialSpecies_(0)
+void PDSS_IonsFromNeutral::setParent(VPStandardStateTP* phase, size_t k)
 {
-    if (!spInstalled) {
-        throw CanteraError("PDSS_IonsFromNeutral", "sp installing not done yet");
-    }
-    std::string id = "";
-    constructPDSSXML(tp, spindex, speciesNode, phaseRoot, id);
+    neutralMoleculePhase_ = dynamic_cast<IonsFromNeutralVPSSTP&>(*phase).neutralMoleculePhase_;
 }
 
-void PDSS_IonsFromNeutral::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
-        const XML_Node& speciesNode,
-        const XML_Node& phaseNode, const std::string& id)
+void PDSS_IonsFromNeutral::setParametersFromXML(const XML_Node& speciesNode)
 {
+    PDSS::setParametersFromXML(speciesNode);
     const XML_Node* tn = speciesNode.findByName("thermo");
     if (!tn) {
         throw CanteraError("PDSS_IonsFromNeutral::constructPDSSXML",
@@ -60,22 +49,9 @@ void PDSS_IonsFromNeutral::constructPDSSXML(VPStandardStateTP* tp, size_t spinde
                            "no Thermo::neutralSpeciesMultipliers Node for species " + speciesNode.name());
     }
 
-    IonsFromNeutralVPSSTP* ionPhase = dynamic_cast<IonsFromNeutralVPSSTP*>(tp);
-    if (!ionPhase) {
-        throw CanteraError("PDSS_IonsFromNeutral::constructPDSSXML", "Dynamic cast failed");
-    }
-    neutralMoleculePhase_ = ionPhase->neutralMoleculePhase_;
+    neutralSpeciesMultipliers_ = parseCompString(nsm->value());
+    numMult_ = neutralSpeciesMultipliers_.size();
 
-    std::vector<std::string> key;
-    std::vector<std::string> val;
-    numMult_ = getPairs(*nsm, key, val);
-    idNeutralMoleculeVec.resize(numMult_);
-    factorVec.resize(numMult_);
-    tmpNM.resize(neutralMoleculePhase_->nSpecies());
-    for (size_t i = 0; i < numMult_; i++) {
-        idNeutralMoleculeVec[i] = neutralMoleculePhase_->speciesIndex(key[i]);
-        factorVec[i] = fpValueCheck(val[i]);
-    }
     specialSpecies_ = 0;
     const XML_Node* ss = tn->findByName("specialSpecies");
     if (ss) {
@@ -97,6 +73,11 @@ void PDSS_IonsFromNeutral::initThermo()
     m_p0 = neutralMoleculePhase_->refPressure();
     m_minTemp = neutralMoleculePhase_->minTemp();
     m_maxTemp = neutralMoleculePhase_->maxTemp();
+    tmpNM.resize(neutralMoleculePhase_->nSpecies());
+    for (auto multiplier : neutralSpeciesMultipliers_) {
+        idNeutralMoleculeVec.push_back( neutralMoleculePhase_->speciesIndex(multiplier.first));
+        factorVec.push_back(multiplier.second);
+    }
 }
 
 doublereal PDSS_IonsFromNeutral::enthalpy_RT() const
diff --git a/src/thermo/PDSS_SSVol.cpp b/src/thermo/PDSS_SSVol.cpp
index 5c7a1cbb8..6ed07a085 100644
--- a/src/thermo/PDSS_SSVol.cpp
+++ b/src/thermo/PDSS_SSVol.cpp
@@ -15,37 +15,19 @@ using namespace std;
 
 namespace Cantera
 {
-PDSS_SSVol::PDSS_SSVol(VPStandardStateTP* tp, size_t spindex) :
-    PDSS(tp, spindex),
-    volumeModel_(SSVolume_Model::constant),
-    m_constMolarVolume(-1.0)
+
+PDSS_SSVol::PDSS_SSVol()
+    : volumeModel_(SSVolume_Model::constant)
+    , m_constMolarVolume(-1.0)
 {
     TCoeff_[0] = 0.0;
     TCoeff_[1] = 0.0;
     TCoeff_[2] = 0.0;
 }
 
-PDSS_SSVol::PDSS_SSVol(VPStandardStateTP* tp, size_t spindex,
-                       const XML_Node& speciesNode,
-                       const XML_Node& phaseRoot,
-                       bool spInstalled) :
-    PDSS(tp, spindex),
-    volumeModel_(SSVolume_Model::constant),
-    m_constMolarVolume(-1.0)
+void PDSS_SSVol::setParametersFromXML(const XML_Node& speciesNode)
 {
-    constructPDSSXML(tp, spindex, speciesNode, phaseRoot, spInstalled);
-}
-
-void PDSS_SSVol::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
-                                  const XML_Node& speciesNode,
-                                  const XML_Node& phaseNode, bool spInstalled)
-{
-    PDSS::initThermo();
-    m_p0 = m_tp->speciesThermo().refPressure(m_spindex);
-
-    if (!spInstalled) {
-        throw CanteraError("PDSS_SSVol::constructPDSSXML", "spInstalled false not handled");
-    }
+    PDSS::setParametersFromXML(speciesNode);
 
     const XML_Node* ss = speciesNode.findByName("standardState");
     if (!ss) {
@@ -76,19 +58,12 @@ void PDSS_SSVol::constructPDSSXML(VPStandardStateTP* tp, size_t spindex,
     }
 }
 
-void PDSS_SSVol::initThermoXML(const XML_Node& phaseNode, const std::string& id)
-{
-    PDSS::initThermoXML(phaseNode, id);
-    m_minTemp = m_spthermo->minTemp(m_spindex);
-    m_maxTemp = m_spthermo->maxTemp(m_spindex);
-    m_p0 = m_spthermo->refPressure(m_spindex);
-    m_mw = m_tp->molecularWeight(m_spindex);
-}
-
 void PDSS_SSVol::initThermo()
 {
     PDSS::initThermo();
-    m_p0 = m_tp->speciesThermo().refPressure(m_spindex);
+    m_minTemp = m_spthermo->minTemp();
+    m_maxTemp = m_spthermo->maxTemp();
+    m_p0 = m_spthermo->refPressure();
     m_V0 = m_constMolarVolume;
     m_Vss = m_constMolarVolume;
 }
@@ -147,7 +122,7 @@ void PDSS_SSVol::setPressure(doublereal p)
 void PDSS_SSVol::setTemperature(doublereal temp)
 {
     m_temp = temp;
-    m_spthermo->update_single(m_spindex, temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
+    m_spthermo->updatePropertiesTemp(temp, &m_cp0_R, &m_h0_RT, &m_s0_R);
     calcMolarVolume();
     m_g0_RT = m_h0_RT - m_s0_R;
     doublereal deltaP = m_pres - m_p0;
diff --git a/src/thermo/PDSS_Water.cpp b/src/thermo/PDSS_Water.cpp
index f8eaf1fa8..371c6da6f 100644
--- a/src/thermo/PDSS_Water.cpp
+++ b/src/thermo/PDSS_Water.cpp
@@ -9,6 +9,7 @@
 #include "cantera/thermo/PDSS_Water.h"
 #include "cantera/thermo/WaterPropsIAPWS.h"
 #include "cantera/base/stringUtils.h"
+#include "cantera/thermo/Elements.h"
 
 namespace Cantera
 {
@@ -18,62 +19,11 @@ PDSS_Water::PDSS_Water() :
     m_iState(WATER_LIQUID),
     EW_Offset(0.0),
     SW_Offset(0.0),
-    m_verbose(0),
     m_allowGasPhase(false)
 {
-    m_spthermo = 0;
-    constructSet();
     m_minTemp = 200.;
     m_maxTemp = 10000.;
-}
-
-PDSS_Water::PDSS_Water(VPStandardStateTP* tp, int spindex) :
-    PDSS(tp, spindex),
-    m_waterProps(&m_sub),
-    m_dens(1000.0),
-    m_iState(WATER_LIQUID),
-    EW_Offset(0.0),
-    SW_Offset(0.0),
-    m_verbose(0),
-    m_allowGasPhase(false)
-{
-    m_spthermo = 0;
-    constructSet();
-    m_minTemp = 200.;
-    m_maxTemp = 10000.;
-}
-
-PDSS_Water::PDSS_Water(VPStandardStateTP* tp, int spindex,
-                       const XML_Node& speciesNode,
-                       const XML_Node& phaseRoot, bool spInstalled) :
-    PDSS(tp, spindex),
-    m_waterProps(&m_sub),
-    m_dens(1000.0),
-    m_iState(WATER_LIQUID),
-    EW_Offset(0.0),
-    SW_Offset(0.0),
-    m_verbose(0),
-    m_allowGasPhase(false)
-{
-    std::string id= "";
-    constructPDSSXML(tp, spindex, phaseRoot, id);
-    initThermo();
-    m_spthermo = 0;
-    m_minTemp = 200.;
-    m_maxTemp = 10000.;
-}
-
-void PDSS_Water::constructPDSSXML(VPStandardStateTP* tp, int spindex,
-                                  const XML_Node& phaseNode, const std::string& id)
-{
-    constructSet();
-}
-
-void PDSS_Water::constructSet()
-{
-    // Calculate the molecular weight. hard coded to Cantera's elements and
-    // Water.
-    m_mw = 2 * 1.00794 + 15.9994;
+    m_mw = 2*getElementWeight("H") + getElementWeight("O");
 
     // Set the baseline
     doublereal T = 298.15;
diff --git a/src/thermo/VPStandardStateTP.cpp b/src/thermo/VPStandardStateTP.cpp
index 793266d16..4a3b7273e 100644
--- a/src/thermo/VPStandardStateTP.cpp
+++ b/src/thermo/VPStandardStateTP.cpp
@@ -17,6 +17,7 @@
 #include "cantera/thermo/PDSS_SSVol.h"
 #include "cantera/thermo/PDSS_HKFT.h"
 #include "cantera/thermo/PDSS_IonsFromNeutral.h"
+#include "cantera/thermo/IonsFromNeutralVPSSTP.h"
 #include "cantera/thermo/SpeciesThermoFactory.h"
 #include "cantera/base/utilities.h"
 #include "cantera/base/ctml.h"
@@ -188,9 +189,11 @@ void VPStandardStateTP::initThermo()
     ThermoPhase::initThermo();
     for (size_t k = 0; k < m_kk; k++) {
         PDSS* kPDSS = m_PDSS_storage[k].get();
-        if (kPDSS) {
-            kPDSS->initThermo();
+        if (kPDSS == 0) {
+            throw CanteraError("VPStandardStateTP::initThermo",
+                "No PDSS object for species {}", k);
         }
+        kPDSS->initThermo();
     }
 }
 
@@ -260,43 +263,40 @@ void VPStandardStateTP::createInstallPDSS(size_t k, const XML_Node& s,
         m_PDSS_storage.resize(k+1);
     }
     PDSS* kPDSS = nullptr;
-    bool use_STITbyPDSS;
 
     const XML_Node* const ss = s.findByName("standardState");
     if (!ss) {
-        use_STITbyPDSS = false;
-        kPDSS = new PDSS_IdealGas(this, k, s, *phaseNode, true);
+        kPDSS = new PDSS_IdealGas();
     } else {
         std::string model = ss->attrib("model");
         if (model == "constant_incompressible") {
-            kPDSS = new PDSS_ConstVol(this, k, s, *phaseNode, true);
-            use_STITbyPDSS = false;
+            kPDSS = new PDSS_ConstVol();
         } else if (model == "waterIAPWS" || model == "waterPDSS") {
-            kPDSS = new PDSS_Water(this, 0);
-            use_STITbyPDSS = true;
+            kPDSS = new PDSS_Water();
             m_useTmpRefStateStorage = false;
         } else if (model == "HKFT") {
-            kPDSS = new PDSS_HKFT(this, k, s, *phaseNode, true);
-            use_STITbyPDSS = true;
+            kPDSS = new PDSS_HKFT();
         } else if (model == "IonFromNeutral") {
-            kPDSS = new PDSS_IonsFromNeutral(this, k, s, *phaseNode, true);
-            use_STITbyPDSS = true;
+            kPDSS = new PDSS_IonsFromNeutral();
         } else if (model == "constant" || model == "temperature_polynomial" || model == "density_temperature_polynomial") {
-            kPDSS = new PDSS_SSVol(this, k, s, *phaseNode, true);
-            use_STITbyPDSS = false;
+            kPDSS = new PDSS_SSVol();
         } else {
             throw CanteraError("VPStandardStateTP::createInstallPDSS",
                                "unknown standard state formulation: " + model);
         }
     }
+    kPDSS->setParent(this, k);
+    kPDSS->setMolecularWeight(molecularWeight(k));
+    kPDSS->setParametersFromXML(s);
 
-    if (use_STITbyPDSS) {
+    if (kPDSS->useSTITbyPDSS()) {
         auto stit = make_shared<STITbyPDSS>(kPDSS);
         m_spthermo.install_STIT(k, stit);
     } else {
         shared_ptr<SpeciesThermoInterpType> stit(
             newSpeciesThermoInterpType(s.child("thermo")));
         stit->validate(s["name"]);
+        kPDSS->setReferenceThermo(stit);
         m_spthermo.install_STIT(k, stit);
     }
 
@@ -319,18 +319,6 @@ void VPStandardStateTP::invalidateCache()
     m_Tlast_ss += 0.0001234;
 }
 
-void VPStandardStateTP::initThermoXML(XML_Node& phaseNode, const std::string& id)
-{
-    for (size_t k = 0; k < m_kk; k++) {
-        PDSS* kPDSS = m_PDSS_storage[k].get();
-        AssertTrace(kPDSS != 0);
-        if (kPDSS) {
-            kPDSS->initThermoXML(phaseNode, id);
-        }
-    }
-    ThermoPhase::initThermoXML(phaseNode, id);
-}
-
 void VPStandardStateTP::_updateStandardStateThermo() const
 {
     double Tnow = temperature();
diff --git a/test_problems/cathermo/testWaterPDSS/testWaterPDSS.cpp b/test_problems/cathermo/testWaterPDSS/testWaterPDSS.cpp
index 7725ab30f..9816bd930 100644
--- a/test_problems/cathermo/testWaterPDSS/testWaterPDSS.cpp
+++ b/test_problems/cathermo/testWaterPDSS/testWaterPDSS.cpp
@@ -23,8 +23,7 @@ int main()
 #endif
     double pres;
     try {
-        Cantera::VPStandardStateTP* nnn = 0;
-        Cantera::PDSS_Water* w = new Cantera::PDSS_Water(nnn, 0);
+        Cantera::PDSS_Water* w = new PDSS_Water();
 
         /*
          * Print out the triple point conditions