Redetermination of the Intermolecular Potential for Krypton

Abstract

The intermolecular potential for krypton has been redetermined from transport property data, including new experimental results on thermal diffusion and thermal conductivity. Both the Lennard-Jones (12–6) and the exp-6 potential functions have been used and reproduce the data about equally well. The parameter α of the exp-6 potential is not uniquely determined by the data, but a tentative selection of α=13.5 has been made semiempirically on the basis of the theory of the dispersion energy and the consistency with the other rare-gas potentials. The most important conclusion is that there is a large discrepancy, not found for the other rare gases, between the present results and the experimental crystal properties and second virial coefficient. No amount of parameter adjustment has been able to reduce the discrepancy to a reasonably acceptable value. Possible explanations and implications of this unusual and unsatisfactory situation are discussed.