We chose the units of properties and weights (w 1 -w 5 ) for the mean square error constraints in part to emulate parameterization conditions used in the development of IAPWS95 equation of state, specifically the liquid region as we restrict our water model for the liquid region. IAPWS95 used experimental properties of both the liquid and gas phases as well as the phase equilibrium data for parameterizing the IAPWS95 equation of state. We instead focus specifically on the liquid region, so molar volume or density, isobaric heat capacity, internal energy and isothermal compressibility are the most important experimental observables for us as they capture the pressure and temperature derivatives of the Gibbs energy surface for liquid water. Experimental isothermal compressibility data was not used while fitting IAPWS95.