Path-integral calculation of the second virial coefficient including intramolecular flexibility effects

Giovanni Garberoglio; Piotr Jankowski; Krzysztof Szalewicz; Allan H Harvey

doi:10.1063/1.4890440

Path-integral calculation of the second virial coefficient including intramolecular flexibility effects

J Chem Phys. 2014 Jul 28;141(4):044119. doi: 10.1063/1.4890440.

Authors

Giovanni Garberoglio¹, Piotr Jankowski², Krzysztof Szalewicz³, Allan H Harvey⁴

Affiliations

¹ Interdisciplinary Laboratory for Computational Science (LISC), FBK-CMM and University of Trento, via Sommarive 18, I-38123 Povo (TN), Italy.
² Department of Quantum Chemistry, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, PL-87-100 Toruń, Poland.
³ Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.
⁴ Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, USA.

PMID: 25084893
DOI: 10.1063/1.4890440

Abstract

We present a path-integral Monte Carlo procedure for the fully quantum calculation of the second molecular virial coefficient accounting for intramolecular flexibility. This method is applied to molecular hydrogen (H2) and deuterium (D2) in the temperature range 15-2000 K, showing that the effect of molecular flexibility is not negligible. Our results are in good agreement with experimental data, as well as with virials given by recent empirical equations of state, although some discrepancies are observed for H2 between 100 and 200 K.