Elastic constants of noble-gas crystals under pressure and the cauchy relations

The equations of state are solved and the elastic constants responsible for the propagation of sound in strongly compressed crystals of noble gases are calculated in the next-to-nearest neighbor approximation using the interatomic potential proposed by the authors. The results of calculations are in satisfactory agreement with the experimental data. Slightly worse agreement is achieved in calculating the shear modulus ℬ44. The validity of the Cauchy relation for krypton is confirmed in the experiment. On this basis, the inference is drawn that the interatomic interaction in the krypton crystal has a central character.