Cross second virial coefficients of the N₂–H₂, O₂–H₂, and CO₂–H₂ systems from first principles

Hellmann, Robert; Bich, Eckard

doi:10.1007/s10765-025-03524-6

Cross second virial coefficients of the N₂–H₂, O₂–H₂, and CO₂–H₂ systems from first principles

Publication date

2025-03-15

Document type

Forschungsartikel

Author

Hellmann, Robert

Bich, Eckard

Organisational unit

Thermodynamik

DTEC.bw

DOI

10.1007/s10765-025-03524-6

URI

https://openhsu.ub.hsu-hh.de/handle/10.24405/21240

Project

Computergestützte und experimentelle Bestimmung der thermophysikalischen Eigenschaften von wasserstoffhaltigen Gasgemischen

Publisher

Springer Science + Business Media

Series or journal

International Journal of Thermophysics

ISSN

0195-928X

Periodical volume

46

Periodical issue

5

Article ID

67

Peer-reviewed

✅

Part of the university bibliography

✅

Language

English

Abstract

The cross second virial coefficients B_12 for interactions of molecular nitrogen (N₂) with molecular hydrogen (H₂), of molecular oxygen (O₂) with H2, and of carbon dioxide (CO₂) with H₂ were obtained at temperatures ranging from 36 K to 2000 K for the former two systems and from 100 K to 2000 K for the latter system from new rigid-rotor intermolecular potential energy surfaces (PESs) for the three molecule pairs. Each PES is based on interaction energies calculated for a large number of pair configurations employing high-level quantum-chemical ab initio methods up to coupled cluster with single, double, triple, and perturbative quadruple excitations [CCSDT(Q)]. Core-core and core-valance correlation and relativistic effects were accounted for as well. B_12 values were extracted from the PESs classically and semiclassically using the Mayer-sampling Monte Carlo approach. The deficiencies of the semiclassical calculations at the lowest temperatures were partly remedied by a more rigorous treatment of translational quantum effects using the phase-shift method. The results for the N2–H2 and CO₂–H₂ systems are in excellent agreement with the most accurate experimental data. For the O₂–H₂ system, there are no experimental B_12 data because this mixture is highly explosive. There are, however, previous first-principles results for B_12 of this system by Van Tat and Deiters [Chem. Phys. 457, 171–179 (2015)], which were obtained at a much lower level of sophistication for both the PES and the method to extract B_12 and differ significantly from the present values.

Description

This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).

Cite as

Int. J. Thermophys. (2025) 46:67

Version

Published version

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Metadata only access

Open Access Funding

Springer Nature (DEAL)