Solid-State Modeling of the Terahertz Spectrum of the High Explosive HMX
- 14 January 2006
- journal article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry A
- Vol. 110 (5), 1951-1959
- https://doi.org/10.1021/jp0554285
Abstract
The experimental solid-state terahertz (THz) spectrum (3-120 cm(-1)) of the beta-crystal form of the high explosive octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) has been analyzed using solid-state density functional theory calculations. Various density functionals (both generalized gradient approximation and local density approximation) are compared in terms of their abilities to reproduce the experimentally observed solid-state structure and low-frequency vibrational motions. Good-to-excellent agreement between solid-state theory and experiment can be achieved in the THz region where isolated-molecule calculations fail to reproduce the observed spectral features, demonstrating a clear limitation of using isolated-molecule calculations for the assignment of THz frequency motions in molecular solids. The deficiency of isolated-molecule calculations is traced to modification of the molecular structure in the solid state through crystal packing effects and the formation of weak C-H...O hydrogen bonds.This publication has 26 references indexed in Scilit:
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