We compute the hydrogen vibrational spectra for bulk ammonia borane (NH3BH3) using harmonic and anharmonic methodologies as well as quantifying dispersive effects to determine their influence on the resulting spectra. Even at 10K the accounting of anharmonic effects on the IINS signal are more significant than approximations introduced by sampling and interpolating a finite simulation cell to capture dispersion effects. We compare our computed anharmonic power spectrum with IINS spectral measurements and find excellent agreement. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.
Revised: April 17, 2012 |
Published: March 8, 2012
Citation
Kathmann S.M., C.J. Mundy, G.K. Schenter, T. Autrey, P.C. Aeberhard, W. David, and M.O. Jones, et al. 2012.Understanding Vibrational Anharmonicity and Phonon Dispersion in Solid Ammonia Borane.Journal of Physical Chemistry C 116, no. 9:5926-5931.PNNL-SA-75483.doi:10.1021/jp207540x