Effective Intermolecular Interaction Potentials of Gaseous Fluorine, Chlorine, Bromine, and Iodine

Abstract

Results are presented for binary intermolecular interactions and thermophysical properties in the temperature range between 70 K and 1,000 K of gaseous fluorine (F 2 ), and between 200 K and 1,000 K of chlorine (Cl 2 ), bromine (Br 2 ), and iodine (I 2 ). Our studies are carried out with an (n − 6) Lennard-Jones temperaturedependent potential (LJTDP). The underlying model takes into account the influence of vibrational excitations on the equilibrium distance R m (T ) and potential well depth ε(T ). The potential parameters at T = 0 K have been obtained by minimization of the sum of squared deviations between experimentally determined and calculated second pVT-and acoustic virial coefficients, B and β, and viscosities η, normalized to their relative experimental error a exp . The majority of the available experimental data are well reproduced within their experimental errors. Tables and fitting formulae for a fast and reliable prediction of the thermophysical properties and potential parameters are also presented.

Modified 2CLJDQP model and the second virial coefficients for linear molecules

“…[34,35,38] Hohm and Zarkova [39] presented a Lennard-Jones (n-6) temperature-dependent potential (LJTDP), which is very suitable for globular molecules and can be extended to simple linear molecules. [40,41] Then some different temperature-dependent functions such as linear, [42] double-exponential, [27] hyperbolic, [36] etc. were proposed.…”