Pset_MaterialEnergy A set of extended material properties for energy calculation purposes. IfcMaterial IfcMaterial ViscosityTemperatureDerivative Viscosity temperature derivative. Viscosity Temperature Derivative MoistureCapacityThermalGradient Thermal gradient coefficient for moisture capacity. Based on water vapor density. Moisture Capacity Thermal Gradient ThermalConductivityTemperatureDerivative Thermal conductivity temperature derivative. Thermal Conductivity Temperature Derivative SpecificHeatTemperatureDerivative Specific heat temperature derivative. Specific Heat Temperature Derivative VisibleRefractionIndex Index of refraction (visible) defines the "bending" of the sola! r ray in the visible spectrum when it passes from one medium into another. Visible Refraction Index SolarRefractionIndex Index of refraction (solar) defines the "bending" of the solar ray when it passes from one medium into another. Solar Refraction Index GasPressure Fill pressure (e.g. for between-pane gas fills): the pressure exerted by a mass of gas confined in a constant volume. Gas Pressure