Temperature-dependent interaction potential between NF_3 molecules and thermophysical properties of gaseous NF_3

摘要

A temperature-dependent effective intermolecular interaction potential is applied to describe the interaction between two nitrogen fluoride (NF_3) molecules in gas phase. To this end, a spherically-symmetric (n-6) Lennard-Jones temperature-dependent potential (LJTDP) is used. The (n-6) LJTDP takes into account the influence of vibrational excitation of the molecules on the potential parameters, namely, the equilibrium distance r_m and the potential well depth ε. The potential parameters at T = 0 K were obtained from the very small amount of existing thermophysical equilibrium and transport properties of low-density NF3 gas. Fitting formulae are tabulated for a fast and reliable prediction of the thermophysical properties and potential parameters in the temperature range between 200 K and 1200 K. A comparison is also presented between our estimates for some thermophysical properties of the NF_3 gas with the available experimental and calculated data.