NIST - National Institute of Standards and Technology
10/15/2026 | Press release | Distributed by Public on 10/16/2026 03:08
Recommended Second Virial Coefficients for Nitrogen and Oxygen
Published
October 15, 2026
Author(s)
Robert Hellmann, Giovanni Garberoglio, Allan Harvey
Abstract
We provide recommended values for the second virial coefficient, B(T), and its uncertainty, for molecular nitrogen and oxygen. The temperature range covered is 20-3000 K for nitrogen and 20-2000 K for oxygen. The recommendations are based on tuning previously published state-of-the-art ab initio pair potentials so that the B(T) calculated from the potentials match selected high-accuracy experimental data; for nitrogen the tuning utilizes values of B derived from literature density data with greatly reduced uncertainty by analyzing the data with the aid of ab initio calculated higher virial coefficients. Quantum effects on B are fully included with the path-integral Monte Carlo method. The resulting B(T) have uncertainties similar to those of the best experimental data, but cover a much wider temperature range.
Citation
J. Phys. & Chem. Ref. Data (JPCRD) -
Volume
55
Issue
4
NIST Pub Series
Pub Type
NIST Pubs
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Keywords
air, metrology, nitrogen, oxygen, thermodynamics, virial coefficient
Citation
Hellmann, R. , Garberoglio, G. and Harvey, A. (2026), Recommended Second Virial Coefficients for Nitrogen and Oxygen, J. Phys. & Chem. Ref. Data (JPCRD), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.1063/5.0354088, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=962583 (Accessed October 16, 2026)
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NIST - National Institute of Standards and Technology published this content on October 15, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on October 16, 2026 at 09:08 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]