ORIENTATIONAL CORRELATIONS AND CORRESPONDING STATE PRINCIPLE IN LIQUIDS OF LINEAR-MOLECULES

A new method of studying orientational correlations in liquids of linear molecules is presented and applied to N2, F2, Cl2, Br2, I2, CO2 and CS2 near their triple points. The method is based on the subdivision of the total angular space of a pair of molecules into a complete set of disjoint classes of configurations, GAMMA, centered around a given stable dimer geometry. The corresponding state principle is shown to be valid if excluded volume effects, which depend on GAMMA, are taken into account. The comparison of the centres radial distribution functions of each configuration with the radial distribution function of liquid Ar gives information on the role played by specific configurations, and suggests a method of measuring the orientational correlations present in the fluid.