Semiclassical fifth virial coefficients for improved ab initio helium-­4 standards

Published: February 15, 2012


Katherine Shaul, Andrew Schultz, David A. Kofke, Michael R. Moldover


For helium-4, we present ab initio, semi-classical calculations of virial coefficients Bn for for n = 2, 3, 4, and 5 from 50 K to 1000 K. Using our values of B4 and B5 and the more accurate literature values of B2 and B3, we argue that the ab initio virial equation of state is more accurate than recent, high-quality, densimeter measurements spanning the range {223 K < T < 500 K, p < 38 MPa}. Thus, the present values of B4 and B5 extend the useful temperature and density range of ab initio helium standards.
Citation: Chemical Physics Letters
Volume: 531
Pub Type: Journals

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equation of state, helium, gas standards, virial coefficients, thermodynamic standards
Created February 15, 2012, Updated February 19, 2017