Monte Carlo calculations on rare-gas crystals

Abstract

The internal energy U _MC of crystalline Ar, Kr and Xe has been calculated by the Monte Carlo method, using the latest available potentials including contributions from three-body forces and quantum corrections. The values of U _MC are in excellent agreement with experimental values for the cohesive energy. Similar calculations for a system of 107 particles on 108 lattice sites lead to values of the energy to form a Schottky defect (u ₁) in these rare-gas crystals. We have also shown that in krypton u ₁ depends on temperature. Existing data for the temperature dependence of the expansivity and lattice parameter for Ar and Kr have been re-analysed by making use of the calculated values of u ₁ and values of the non-configurational entropy change on forming a vacancy (s ₁) have been evaluated for Ar and Kr. These values of u ₁ and s ₁ are compared with previous experimental and theoretical results.

Additional information

Notes on contributors

P.W.M. Jacobs

Member