The phonon spectrum of phase-I ammonia: reassignment of lattice mode symmetries from combined molecular and lattice dynamics calculations |
| |
Authors: | Reilly Anthony M Middlemiss Derek S Siddick M Murshed Wann Derek A Ackland Graeme J Wilson Chick C Rankin David W H Morrison Carole A |
| |
Affiliation: | School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ UK. |
| |
Abstract: | The zone-center phonon spectra of phase-I ammonia and deuterated ammonia have been obtained from plane-wave DFT molecular dynamics and localized basis set harmonic lattice dynamics simulations. These data have proved to be excellent for benchmarking the two approaches. Significant changes to the assignments of the experimental low-frequency lattice modes are proposed on the basis of the calculated data. The magnitude of the splitting of the longitudinal and transverse optical modes has been determined and is shown to be significant in some cases. The high-frequency internal mode region of the spectrum has also been obtained and is shown to be in excellent agreement with the results of previous studies. The symmetry coordinates and Davydov splittings of the internal modes are fully analyzed. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |