diff --git a/src/thermo/MargulesVPSSTP.cpp b/src/thermo/MargulesVPSSTP.cpp
index 443ea17a0..c440e57fc 100644
--- a/src/thermo/MargulesVPSSTP.cpp
+++ b/src/thermo/MargulesVPSSTP.cpp
@@ -200,6 +200,26 @@ void MargulesVPSSTP::getPartialMolarVolumes(doublereal* vbar) const
 void MargulesVPSSTP::initThermo()
 {
     initLengths();
+    if (m_input.hasKey("interactions")) {
+        for (auto& item : m_input["interactions"].asVector<AnyMap>()) {
+            auto& species = item["species"].asVector<string>(2);
+            vector_fp h(2), s(2), vh(2), vs(2);
+            if (item.hasKey("excess-enthalpy")) {
+                h = item.convertVector("excess-enthalpy", "J/kmol", 2);
+            }
+            if (item.hasKey("excess-entropy")) {
+                s = item.convertVector("excess-entropy", "J/kmol/K", 2);
+            }
+            if (item.hasKey("excess-volume-enthalpy")) {
+                vh = item.convertVector("excess-volume-enthalpy", "m^3/kmol/K", 2);
+            }
+            if (item.hasKey("excess-volume-entropy")) {
+                vs = item.convertVector("excess-volume-entropy", "m^3/kmol/K", 2);
+            }
+            addBinaryInteraction(species[0], species[1],
+                h[0], h[1], s[0], s[1], vh[0], vh[1], vs[0], vs[1]);
+        }
+    }
     GibbsExcessVPSSTP::initThermo();
 }
 
diff --git a/src/thermo/PDSSFactory.cpp b/src/thermo/PDSSFactory.cpp
index 303accba6..3a57c9fa0 100644
--- a/src/thermo/PDSSFactory.cpp
+++ b/src/thermo/PDSSFactory.cpp
@@ -22,6 +22,7 @@ PDSSFactory::PDSSFactory()
     reg("ideal-gas", []() { return new PDSS_IdealGas(); });
     reg("constant-incompressible", []() { return new PDSS_ConstVol(); });
     m_synonyms["constant_incompressible"] = "constant-incompressible";
+    m_synonyms["constant-volume"] = "constant-incompressible";
     reg("water", []() { return new PDSS_Water(); });
     m_synonyms["waterPDSS"] = m_synonyms["waterIAPWS"] = "water";
     reg("ions-from-neutral", []() { return new PDSS_IonsFromNeutral(); });
diff --git a/src/thermo/PDSS_ConstVol.cpp b/src/thermo/PDSS_ConstVol.cpp
index 22d45a946..f9653d169 100644
--- a/src/thermo/PDSS_ConstVol.cpp
+++ b/src/thermo/PDSS_ConstVol.cpp
@@ -40,6 +40,9 @@ void PDSS_ConstVol::setParametersFromXML(const XML_Node& speciesNode)
 void PDSS_ConstVol::initThermo()
 {
     PDSS::initThermo();
+    if (m_input.hasKey("molar-volume")) {
+        setMolarVolume(m_input.convert("molar-volume", "m^3/kmol"));
+    }
     m_minTemp = m_spthermo->minTemp();
     m_maxTemp = m_spthermo->maxTemp();
     m_p0 = m_spthermo->refPressure();
diff --git a/test/data/thermo-models.yaml b/test/data/thermo-models.yaml
index 8f726733e..d23901d11 100644
--- a/test/data/thermo-models.yaml
+++ b/test/data/thermo-models.yaml
@@ -19,6 +19,16 @@ phases:
   species: [Li]
   chemical-potential: -2.3e7 J/kmol
 
+- name: molten-salt-Margules
+  thermo: Margules
+  species: [KCl(l), LiCl(l)]
+  state: {T: 900, P: 101325, X: {KCl(l): 0.3, LiCl(l): 0.7}}
+  units: {quantity: gmol}
+  interactions:
+  - species: [KCl(l), LiCl(l)]
+    excess-enthalpy: [-17570, -377]
+    excess-entropy: [-7.627, 4.958]
+
 species:
 - name: NaCl(s)
   composition: {Na: 1, Cl: 1}
@@ -50,3 +60,25 @@ species:
 
 - name: Li
   composition: {Li: 1}
+
+- name: KCl(l)
+  composition: {K: 1, Cl: 1}
+  thermo:
+    model: Shomate
+    temperature-ranges: [700, 2000]
+    data:
+    - [73.59698, 0.0, 0.0, 0.0, 0.0, -443.7341, 175.7209]
+  equation-of-state:
+    model: constant-volume
+    molar-volume: 37.57 cm^3/gmol
+
+- name: LiCl(l)
+  composition: {Li: 1, Cl: 1}
+  thermo:
+    model: Shomate
+    temperature-ranges: [700, 2000]
+    data:
+    - [73.18025, -9.047232, -0.316390, 0.079587, 0.013594, -417.1314, 157.6711]
+  equation-of-state:
+    model: constant-volume
+    molar-volume: 20.304 cm^3/gmol
diff --git a/test/thermo/thermoFromYaml.cpp b/test/thermo/thermoFromYaml.cpp
index fd641b0e6..397100eb3 100644
--- a/test/thermo/thermoFromYaml.cpp
+++ b/test/thermo/thermoFromYaml.cpp
@@ -113,3 +113,16 @@ TEST(ThermoFromYaml, FixedChemPot)
     thermo->getChemPotentials(&mu);
     EXPECT_DOUBLE_EQ(mu, -2.3e7);
 }
+
+TEST(ThermoFromYaml, Margules)
+{
+    AnyMap infile = AnyMap::fromYamlFile("thermo-models.yaml");
+    auto phaseNodes = infile["phases"].asMap("name");
+    auto thermo = newPhase(*phaseNodes.at("molten-salt-Margules"), infile);
+    EXPECT_EQ(thermo->type(), "Margules");
+
+    // Regression test based on LiKCl_liquid.xml
+    EXPECT_NEAR(thermo->density(), 2042.1165603245981, 1e-9);
+    EXPECT_NEAR(thermo->gibbs_mass(), -9682981.421693124, 1e-5);
+    EXPECT_NEAR(thermo->cp_mole(), 67478.48085733457, 1e-8);
+}