Fully quantum calculation of the second and third virial coefficients of water and its isotopologues from ab initio potentials

Published: December 20, 2018

Author(s)

Giovanni Garberoglio, Piotr Jankowski, Krzysztof Szalewicz, Allan H. Harvey

Abstract

Path-integral Monte Carlo methods were applied to calculate the second virial coefficient B(T) and the third virial coefficient C(T) in a fully quantum way for state-of-the-art flexible pair and three-body potentials for water. The use of flexible potentials allows calculations for any isotopologue; we performed calculations for both H2O and D2O. For B(T), we find that the effect of flexibility, while not as large as some claims in the literature, is significant compared to the experimental uncertainty. When flexibility is fully accounted for, results from the CCpol- 8sf pair potential are in excellent agreement with the available experimental data. The flexible MB-pol pair potential yields B(T) that are slightly too high compared to experiment. For C(T), our calculations confirm the relative importance of the three-body potential. It appears that none of the currently available three-body potentials is adequate for quantitatively accurate prediction of C(T).
Citation: Faraday Discussions
Volume: 212
Pub Type: Journals

Keywords

computational chemistry, heavy water, virial coefficients, water
Created December 20, 2018, Updated December 20, 2018