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The four-body nonadditive potential energy surface and the fourth virial coefficient of helium

Published

Author(s)

Richard J. Wheatley, Giovanni Garberoglio, Allan H. Harvey

Abstract

The four-body nonadditive contribution to the energy of four helium atoms is calculated and fitted for all geometries for which the internuclear distances exceed a small minimum value. The interpolation uses an active learning approach based on Gaussian processes. Asymptotic functions are used to calculate the nonadditive energy when the four helium atoms form distinct subclusters. The resulting four-body potential is used to compute the fourth virial coefficient D(T) for helium, at temperatures from 10 to 2000 K, with a path-integral approach that fully accounts for quantum effects. The results are in reasonable agreement with the limited and scattered experimental data for D(T), but our calculated results have much smaller uncertainties.
Citation
Journal of Chemical and Engineering Data
Volume
68
Issue
12

Keywords

helium, intermolecular forces, metrology, virial coefficients

Citation

Wheatley, R. , Garberoglio, G. and Harvey, A. (2023), The four-body nonadditive potential energy surface and the fourth virial coefficient of helium, Journal of Chemical and Engineering Data, [online], https://doi.org/10.1021/acs.jced.3c00578, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956656 (Accessed April 27, 2024)
Created November 29, 2023, Updated December 14, 2023