A modified thermodynamic perturbation theory of Wertheim for heteronuclear molecules

Abstract

The Wertheim thermodynamic perturbation theory (TPT1) is modified for fluids of heteronuclear molecules. The equation proposed by Mansoori–Carnahan–Starling and Leland has been applied for monomers instead of the Carnahan–Starling equation. The modified TPT is compared with simulation results and other theoretical results for heteronuclear dimer, trimer, and higher mers covering a wide range of size ratios. The modified TPT gives a useful method of extending the original TPT1 model to molecules of heteronuclear hard sphere cores without introducing any parameter such as shape factor α.