Abstract Victorov A.I. and Fredenslund Aa., 1991. Application of the hole quasi-chemical group contribution equation of state for phase equilibrium calculation in systems with association. Fluid Phase Equilibria, 66: 77-101. Hole group contribution quasi-chemical model parameters for mixtures containing methanol, water and acetone together with light and heavy alkanes, nitrogen, hydrogen sulfide and carbon dioxide are determined. A list of model parameters is given, encompassing about 30 different functional groups. The results of liquid-gas and liquid-liquid equilibrium calculations for many binary and several multicomponent mixtures at normal and elevated pressures (up to 40 MPa) are discussed.