Simulation studies of liquid ammonia by classical ab initio, classical, and path-integral molecular dynamics

M. Diraison, G. J. Martyna, Mark Tuckerman

Research output: Contribution to journalArticle

Abstract

The structure of liquid ammonia at T=273 K has been studied using classical ab initio molecular dynamics, classical molecular dynamics, and the path-integral molecular dynamics methods. The three different types of calculation are employed to generate new insights into the ability of theoretical methods to model liquid ammonia effectively. Thus, the limitations of using classical nuclei, simple point charge models, small systems, and gradient corrected density functional theory are assessed through a comparison of the results of the different types of calculations to each other and recent experiments in a consistent manner. Briefly, the experimental intermolecular quantum structure is very well reproduced by the classical approximation while the intramolecular classical and quantum structures exhibit large deviations. The intermolecular ab initio partial radial structure factors of liquid ammonia and the associated radial distribution functions are in better agreement with experiment than the empirical models. However, the empirical models also perform reasonably well.

Original languageEnglish (US)
Pages (from-to)1096-1103
Number of pages8
JournalJournal of Chemical Physics
Volume111
Issue number3
StatePublished - Jul 15 1999

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liquid ammonia
Ammonia
Molecular dynamics
molecular dynamics
Liquids
simulation
radial distribution
Distribution functions
Density functional theory
Experiments
distribution functions
density functional theory
deviation
gradients
nuclei
approximation

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Simulation studies of liquid ammonia by classical ab initio, classical, and path-integral molecular dynamics. / Diraison, M.; Martyna, G. J.; Tuckerman, Mark.

In: Journal of Chemical Physics, Vol. 111, No. 3, 15.07.1999, p. 1096-1103.

Research output: Contribution to journalArticle

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