ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We present statistical mechanical calculations for krypton and xenon, employing accurate pair potentials with and without condensed-phase modifications. A unique feature of the present work is that solid- and fluid-phase thermodynamic properties are both computed within a single framework, using our recently developed hard-sphere perturbation theory. Results are applied to analyze experimental fluid, solid, and fluid–solid transition data, ranging up to 2×106 atmospheres at several temperatures. Effective pair potentials for both krypton and xenon, inferred from the analysis, contain short- and long-range modifications to the pair potential of Aziz and Slaman. The long-range correction is repulsive and originates from the well-known Axilrod–Teller three-body potential, while the short-range correction is attractive and is needed for describing high-compression data. Experimental isotherms above 50 GPa for xenon require a further softening of the short-range repulsion from Barker's correction (obtained from experimental data below 50 GPa). Implications of the short-range correction and its possible relation to many-body forces are discussed. Additional tests of the present rare-gas calculations against available computer simulations and Monte Carlo and lattice-dynamics calculations carried out in this work show satisfactory agreement. Computation of solid–fluid transition properties shows that the Axilrod–Teller three-body potential must be included to obtain reliable agreement with experimental melting and freezing data.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.456935
