Specific Heat Capacity of Light Rare-Gas Crystals in the Model of Deformable Atoms

The model of deformable and polarizable atoms presents ab initio calculations of the specific heat capacity of Ne and Ar crystals under and without pressure. The short-range potential takes into account both the three-body interaction and the deformation of the electron shells of dipole-type atoms in the pair and three- body approximations. The specific heat capacity was studied in a large temperature and pressure range using a dynamic matrix, based on an ab initio short-range repulsive potential and integration over ten main value points of the Chadi – Cohen method. The values of the specific heat capacity of crystalline Ne and Ar increase both under pressure and without it, if we consider the contributions of three-body forces, associated with both the overlap of the electron shells of atoms and the deformation of the electron shells. The comparison of our calculations with those of other authors and experimental data is satisfactory.