Correlations in the Motion of Atoms in Liquid Argon

A. Rahman
Phys. Rev. 136, A405 – Published 19 October 1964
PDFExport Citation

Abstract

A system of 864 particles interacting with a Lennard-Jones potential and obeying classical equations of motion has been studied on a digital computer (CDC 3600) to simulate molecular dynamics in liquid argon at 94.4°K and a density of 1.374 g cm3. The pair-correlation function and the constant of self-diffusion are found to agree well with experiment; the latter is 15% lower than the experimental value. The spectrum of the velocity autocorrelation function shows a broad maximum in the frequency region ω=0.25(kBT). The shape of the Van Hove function Gs(r, t) attains a maximum departure from a Gaussian at about t=3.0×1012 sec and becomes a Gaussian again at about 1011 sec. The Van Hove function Gd(r, t) has been compared with the convolution approximation of Vineyard, showing that this approximation gives a too rapid decay of Gd(r, t) with time. A delayed-convolution approximation has been suggested which gives a better fit with Gd(r, t); this delayed convolution makes Gd(r, t) decay as t4 at short times and as t at long times.

  • Received 6 May 1964

DOI:https://doi.org/10.1103/PhysRev.136.A405

©1964 American Physical Society

Authors & Affiliations

A. Rahman

  • Argonne National Laboratory, Argonne, Illinois

References (Subscription Required)

Click to Expand
Issue

Vol. 136, Iss. 2A — October 1964

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Journals Archive

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×