Anharmonic Linewidth Calculation in 1,4-Dibromobenzeneand Disordered 1,4-Bromochlorobenzene

Abstract

As a natural extension of a preceding work on the vibrational linewidths in two isomorphic 1,4-dihalobenzenes crystals (DBB and BCB, which is orientationally disordered), calculations of the anharmonic contribution to the linewidths have been performed. The calculations show that the decay mechanisms that were previously postulated are compatible with the inter-molecular potential. Some corrections to previous results are illustrated. The disorder contribution to the linewidth and its dependence on the relaxing mode are briefly discussed.

Key Words:

• Anharmonic linewidth calculation
• vibrational relaxation
• orientational disorder
• 1,4-dibrornobenzene
• 1,4-bromochlorobenzene