Refprop 9 [patched] | Nist

It calculates a vast range of data, including: Thermodynamic: Density, enthalpy, entropy, heat capacity ( ), speed of sound, and vapor pressure. Transport: Viscosity and thermal conductivity.

The software is built on several high-accuracy mathematical models to ensure reliability: nist refprop 9

This is the primary model for most pure fluids, allowing for the computation of all equilibrium properties. It calculates a vast range of data, including:

REFPROP 9.0 is designed to provide "near-experimental" accuracy for fluid properties across gas, liquid, and supercritical states. including: Thermodynamic: Density