Thermodynamic Properties of Solid Ar, Kr, and Xe Based Upon a Short-Range Central Force and the Conventional Perturbation Expansion of the Partition Function

Thermodynamic properties of the rare-gas solids Ar, Kr, and Xe are calculated using phenomenological two-body central potentials. The cubic and quartic anharmonic terms in the crystal Hamiltonian have been included, using conventional perturbation theory. Although some definite discrepancies with experiment exist for T<1/3Tmelting these simple models give a fair over-all account of both the volume and temperature dependence of the Helmholtz energy. However, for T>1/3Tmelting (rms deviations greater than {~}6% of the nearest-neighbor distance), anharmonic contributions to the thermodynamic properties become unrealistically large, indicating, we believe, the breakdown of perturbation theory to the order considered in this work.