Pair Interaction Potential Energy Function from the Extended Principle of Corresponding States for SF6-SF6

Abstract

An iterative inversion procedure is used to obtain the effective isotropic part of the pair-interaction potential for SF_6-SF6 from the extended principle of corresponding states. The Lennard-Jones (12-6) potential energy function is used as the initial model potential required by the method. Over a range of reduced temperature extending
from 1 to 1000 this directly measured potential for SF₆-SF₆
fully agrees with the Hartree-Fock-Dispersion (HFD)-type and
Morse-Morse-Spline-vander Waals (MMSV)-type independently
known potentials. This accurate inverted potential can be used in
the calculation of the orientation-averaged viscosity collision integrals
and the dimensionless ratios which are essential to calculate
other transport properties. Our method can be applied to calculate
the pair-interaction potential with no need for force fitting data and
lengthy multi-parameter fitting procedure in all temperature ranges.