CALCULATION OF THERMAL-EXPANSION AND IMPLICIT PHONON FREQUENCY-SHIFT IN DEUTERATED ANTHRACENE

The calculation of implicit shift to the phonon energies for phonons in deuterated anthracene C14D10 at q = 0 is presented, the explicit shift having been already described. This implicit shift is then compared with the shift obtained by neutron scattering experiments and Raman measurements. The calculation of thermal expansion, compressibility and Gruneisen constants, which occur in the calculation of implicit shift, is also presented and a comparison with the measurements is made. All these results are in rough agreement with their measured counterparts, which therefore strengthens faith in the general approach adopted but at the same time indicates the necessity of improvement in the model for the molecular crystal of deuterated anthracene.