Critical Properties


Enter the 'CAS' no. of compound:

'CAS' no. can  be downloaded at or NIST Webbook


Supply a MDL.mol or '*.m3d' file to estimate critical properties or prepare a speadmd.m3d file to estimate all properties.

MDL.mol files can  be downloaded at or NIST Webbook methods or they can be created by using our Draw Mol File utility

Enter a '.mol' or '.m3d' file:

   For this preliminary analysis, group contribution methods are applied to estimate a few properties. Listed below are the sources for the group contributions. Critical Temperature, boiling temperature: Emami et al., J.Chem.Thermo. 41:530(2009) 41:530(2009)

Critical Pressure: Ambrose, Engineering Science Data Item Number 79030 (1979)

Critical Volume, Heat of Vaporization, Liquid Density at room temperature, Solubility Parameter, Enthalpy of Formation, Gibbs Energy of Formation : Constantinou & Gani, AlChEJ, 40:1697(1994).

Hansen Solubility Parameters ,Stefanis & Panayiotou, int. J. Thermophys, 29:568-585(2008)

For a more rigorous analysis based on molecular simulation, the following properties are available and require an .m3d file:ble and require an .m3d file:

Vapor Pressure, Liquid Density, Phase equillibria, Diffusivity, Enthalpy, Entropy, Critical Locus:

The methodology has been sumarized by Elliott et al, Asia Pacific Journal of Chemical Engineering 2:257(2007)

An updated version is available online at SpeadIntro.pdf

The entire equation of state is generated for the fluid from molecular simulation of molecular interaction energies that have been characterized based on a database of over 500 compounds by the SPEADMD methodology. Computation of phase equilibria requires that each component of a mixture has been simulated. If your component(s) have already been simulated , then we will return your results right away. Otherwise, we need 24 hours to perform the simulation.




Tc    PcMPa w Zc nBPK Tb10
0.0 0.0 0.0 0.0 0.0 0.0
Cp/R(298) Hf(KJ/mol) Gf(KJ/mol) HVaP LMV solParm((J/cm3)^1/2)
0.0 0.0 0.0 0.0 0.0 0.0