MOLECULAR-DYNAMICS SIMULATIONS OF ORIENTATIONAL RELAXATION IN DIPOLARLATTICE - LACK OF DIFFUSIVE DECAY FOR 2ND AND HIGHER RANK CORRELATION-FUNCTIONS

Citation
S. Ravichandran et B. Bagchi, MOLECULAR-DYNAMICS SIMULATIONS OF ORIENTATIONAL RELAXATION IN DIPOLARLATTICE - LACK OF DIFFUSIVE DECAY FOR 2ND AND HIGHER RANK CORRELATION-FUNCTIONS, Journal of physical chemistry, 98(44), 1994, pp. 11242-11245
Citations number
29
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
98
Issue
44
Year of publication
1994
Pages
11242 - 11245
Database
ISI
SICI code
0022-3654(1994)98:44<11242:MSOORI>2.0.ZU;2-V
Abstract
Extensive molecular dynamics simulations have been carried out to calc ulate the orientational correlation functions C-l(t), C-l(t) = [4 pi/( 2l + 1)]Sigma(m=-l)(l) [Y(lm)(Omega(0)) Y-lm(Omega(t))] (where Y-lm(O mega) are the spherical harmonics) of point dipoles in a cubic lattice . The decay of C-1(t) is found to be strikingly different from higher l-correlation functions-the latter do not exhibit diffusive dynamics e ven in the long time. Both the cumulant expansion expression of Lynden -Bell and the conventional memory function equation provide very good description of the C-1(t) in the short time but fail to reproduce the observed slow, long time decay of C-1(t).