Solid-State Modeling Of The Terahertz Spectrum Of The High Explosive HMX

Welcoming 2006 with a bang. Or the molecular foundations for a bang, anyway. In the Journal of Physical Chemistry A (J. Phys. Chem. A 2006, 110, 1951). The experimental results were provided by TeraView, Ltd., solid-state calculations with DMol3 from Accelrys.

D. G. Allis, D. A. Prokhorova, and T. M. Korter

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.

Advanced Molecular Manufacturing et al. Interview At Nanotech.biz

Sander Olson was kind enough to offer me a chance to speak… er… type my peace in an interview at nanotech.biz. The link to the interview is HERE. I’m the new interviewee in a list that includes such heavy hitters (and friends/collabs) as Robert Freitas, Tihamer Toth-Fejel, Chris Phoenix, and none other than the good Dr. Hall.