Dynamics in crystals of rigid organic molecules: contrasting the phonon frequencies calculated by molecular dynamics with harmonic lattice dynamics for imidazole and 5-azauracil

Autor:	Graeme M. Day, Sarah L. Price, Maurice Leslie, A. E. Gray
Rok vydání:	2004
Předmět:	Lattice energy Molecular model Phonon Chemistry Biophysics Crystal structure Condensed Matter Physics Molecular physics Crystallography Molecular dynamics Lattice (order) Physical and Theoretical Chemistry Anisotropy Multipole expansion Molecular Biology
Zdroj:	Molecular Physics. 102:1067-1083
ISSN:	1362-3028 0026-8976
DOI:	10.1080/00268970412331284208
Popis:	Molecular dynamics simulations have been performed on crystalline imidazole at 100 K and 5-azauracil at 310 K with a model intermolecular potential that includes a distributed multipole representation of the molecular charge distribution using the program DL_MULTI. The anisotropic atom–atom electrostatic model enabled the experimental crystal structures to be reproduced well in a constant pressure simulation and the simulations showed a physically reasonable thermal expansion relative to the minimum in the static lattice energy. The rigid-body molecular motions in a subsequent constant volume simulation were analysed to obtain the k = 0 frequencies corresponding to different symmetry representations, via the translational and rotational velocity autocorrelation functions. These frequencies were contrasted with the corresponding harmonic lattice modes calculated with the same molecular model and intermolecular potential. The agreement was good, with most, but not all, modes decreasing in frequency in the f...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c9b49845ec563203e2f9c409f288348f https://doi.org/10.1080/00268970412331284208 Zobrazit plný text záznamu