EINSTEIN MODEL AND MODERN METHODS IN THE STATISTICAL-THEORY OF CRYSTALS

A connection between various methods of the atomic theory of crystals and the EINSTEIN model is analyzed. It is pointed out that despite the oversimplified choice of a unique mode of vibrations for all atoms, in many cases it provides better results than the DEBYE model does. What is more, a number of methods of the theory of strongly anharmonic crystals can be considered as extensions of the EINSTEIN model which in its turn, is their limiting case when the anharmonic terms and interatomic correlations are neglected. A comparison between some peculiarities and results of such methods is drawn.