Key points are not available for this paper at this time.
The study of polar fluids begun in a previous paper is continued. Calculations for the Stockmayer potential are extended to include the term of order μ6, where μ is the dipole moment. The effects of higher-order terms are then approximated by means of a simple Padé extrapolation procedure, and the liquid-gas coexistence curve is located in this approximation. An orientation-independent but temperature-dependent potential that is thermodynamically equivalent to an arbitrary orientation-dependent potential is introduced and used to assess the lowest-order thermodynamic effects that result from the presence of quadrupole and octupole terms in the pair-potential. Several values of quadrupole and octupole moments representative of a dipolar molecule (HCl) as well as linear molecules (N2, O2 and CO2, for which μ=0) are considered.
Stell et al. (Wed,) studied this question.