Journal article
Pair Correlation Function Integrals: Computation and Use
Department of Chemical and Biochemical Engineering, Technical University of Denmark1
University of Virginia2
Department of Chemistry, Technical University of Denmark3
Physical Chemistry, Department of Chemistry, Technical University of Denmark4
Computer Aided Process Engineering Center, Department of Chemical and Biochemical Engineering, Technical University of Denmark5
We describe a method for extending radial distribution functions obtained from molecular simulations of pure and mixed molecular fluids to arbitrary distances. The method allows total correlation function integrals to be reliably calculated from simulations of relatively small systems. The long-distance behavior of radial distribution functions is determined by requiring that the corresponding direct correlation functions follow certain approximations at long distances.
We have briefly described the method and tested its performance in previous communications [R. Wedberg, J. P. O’Connell, G. H. Peters, and J. Abildskov, Mol. Simul. 36, 1243 (2010); Fluid Phase Equilib. 302, 32 (2011)], but describe here its theoretical basis more thoroughly and derive long-distance approximations for the direct correlation functions.
We describe the numerical implementation of the method in detail, and report numerical tests complementing previous results. Pure molecular fluids are here studied in the isothermal-isobaric ensemble with isothermal compressibilities evaluated from the total correlation function integrals and compared with values derived from volume fluctuations.
For systems where the radial distribution function has structure beyond the sampling limit imposed by the system size, the integration is more reliable, and usually more accurate, than simple integral truncation.
Language: | English |
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Publisher: | American Institute of Physics |
Year: | 2011 |
Pages: | 084113 |
ISSN: | 10897690 and 00219606 |
Types: | Journal article |
DOI: | 10.1063/1.3626799 |
ORCIDs: | Peters, Günther H.J. and Abildskov, Jens |