A calorimetric and thermodynamic investigation of Cs6[(UO2)2(MoO4)3(MoO5)] and calculated phase behaviour in the system (Cs2MoO4 + UO3 + H2O)

•We determined the low temperature heat capacity of Cs6[(UO2)2(MoO4)3(MoO5)].•We determined enthalpy of formation of Cs6[(UO2)2(MoO4)3(MoO5)] by solution calorimetry.•We calculated ΔfG° (298 K) of Cs6[(UO2)2(MoO4)3(MoO5)].•Using obtained data we performed thermodynamic modeling in the Cs2MoO4 + UO3 + H2O aqueous system.