Tarasevych D. Statistical theory of equilibrium characteristics of "classical" crystals and the limits of their thermodynamic stability

The thesis is devoted to the development of the statistical theory of crystals. Being based on its principles, we find the quantum additions to the thermodynamic functions of "classical" (having a relatively small fraction of quantum effects) crystals and, for the first time, we calculate, quantitatively, the deviation of the sublimation line of fcc neon from the "universal" one. We also give a theory of the isotopic effects in the thermodynamic characteristics of the fcc Ar type crystals and demonstrate its good quantitatively agreement with the corresponding numerical "experiments". Besides, the problem of the thermodynamic stability of the real (fcc) and hypo-thetical (bcc) phases of the Ar type crystals is considered and the "universal" spinodal curves for these phases are built. We calculate the deviation of the spinodal line of the fcc Ne from the "universal" one.