Calculation of anharmonic couplings and THz linewidths in crystalline PETN
Abstract
We have developed a method for calculating the cubic anharmonic couplings in molecular crystals for normal modes with the zero wave vector in the framework of classical mechanics, and have applied it, combined with perturbation theory, to obtain the linewidths of all infrared absorption lines of crystalline pentaerythritol tetranitrate in the terahertz region (<100 cm−1). Contributions of the up- and down-conversion processes to the total linewidth were calculated. The computed linewidths are in qualitative agreement with experimental data and the results of molecular dynamics simulations. Quantum corrections to the linewidths in the terahertz region are shown to be negligible.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 12, 2014
- Source ID
- 10.1063/1.4866896
Entities
People
- Andrey Pereverzev
- Donald L. Thompson
- Thomas D. Sewell
Organizations
- Office of Naval Research
- University of Missouri