.TILMedia.BaseClasses.PartialGasObjectFunctions.densityDerivativeWRTpressure_psxi .TILMedia.BaseClasses.PartialGasObjectFunctions.densityDerivativeWRTpressure_psxipartial function densityDerivativeWRTpressure_psxi = TILMedia.BaseClasses.PartialGasObjectFunctionPrototypes.densityDerivativeWRTpressure_psxi;