DETERMINATION OF THE TEMPERATURE DEPENDENCE OF HEAT CAPACITY FOR SOME MOLECULAR CRYSTALS OF NITRO COMPOUNDS

An analysis of the existing approximations used for describing the dependence of heat capacity at a constant volume on the temperature of a molecular crystal has been carried out. It is shown that the considered Debye and Einstein approximations do not enable one to adequately describe the dependence of heat capacity at a constant volume on the temperature of the molecular crystals of nitro compounds. This inference requires the development of special approximations that would describe both low-frequency and high-frequency parts of the vibrational spectra of molecular crystals. This work presents a universal dependence allowing one to describe the dependence of heat capacity at a constant volume on temperature for a number of molecular crystals of nitro compounds. 
   
Author:  Yu. M. Kovalev and V. F. Kuropatenko
Keywords:  equation of state, molecular crystal, Helmholtz energy, Planck constant, Boltzmann constant, Debye approximation, Einstein approximation
Page:  278