Vibrational Dynamics and Heat Capacity of Polyacetylene

Abstract

Phonon dispersion studies have been made on the cis-transoid form of polyacetylene (PA) chain. Unlike the trans-transoid form reported earlier, this conformation shows crossover and repulsion characteristics in the optical modes. Detailed assignments of modes are given, and the predictive value of the heat capacity obtained via the density of states as a function of temperature is reported.

Keywords:

• Crossover
• Heat capacity
• Phonon dispersion
• Polyacetylene
• Repulsion

ACKNOWLEDGMENT

Financial assistance to A. K. and S. P. (under the Junior Research Fellowship scheme) from the Council of Scientific and Industrial Research and to P. T. from the Department of Science and Technology is gratefully acknowledged.