Use of ab initio methods to make phase equilibria predictions using activity coefficient models

摘要: Abstract An important challenge in applied thermodynamics is the prediction of mixture phase behavior without use any experimental data. Current group contribution methods are sometimes, but not always successful this regard. Activity coefficient models, such as UNIQUAC and Wilson, have explicit energy parameters that usually fitted to In communication, we present a unique, new method obtaining values for these parameters. We ab initio quantum mechanics obtain solution Schrodinger equation determine molecular interaction energies resulting from hydrogen-bonding van der Waals interactions. particular, Hartree–Fock (HF) used between pairs clusters, information then model successfully predict behavior. Examples given here methanol+water, ethanol+water, acetic acid+water, formic acid+water mixtures, last which accurately described by current methods. The analogous procedure using Wilson less successful, suggesting greater physical meaning.