A Comparative Study of Imaginary Time Path Integral Based Methods for Quantum Dynamics

TitleA Comparative Study of Imaginary Time Path Integral Based Methods for Quantum Dynamics
Publication TypeJournal Article
Year of Publication2006
AuthorsHone, TD, Rossky, PJ, Voth, GA
JournalJ Chem Phys
Volume124
Pagination154103
Abstract

The recently introduced approximate many-body quantum simulation method, ring polymer molecular dynamics (RPMD), is compared to the centroid molecular dynamics method (CMD). Comparisons of simulation results for liquid para-hydrogen at two state points and liquid ortho-deuterium at one state point are presented. The calculated quantum correlation functions for the two methods are shown to be in good agreement with one another for a large portion of the time spectrum. However, as the quantum mechanical nature of the system increases, RPMD is less accurate in predicting the kinetic energy of the system than is CMD. A simplified and highly efficient algorithm is proposed which largely corrects this deficiency.

DOI10.1063/1.2186636