Theoretical pressure and dielectric second virial coefficients of CO–Ar

Abstract

Using coupled cluster singles and doubles linear response theory and the d-aug-cc-pVTZ basis set extended with a 3s3p2d1f1g set of midbond functions, the interaction induced electric dipole polarisability surface of the CO–Ar van der Waals complex is computed. Combining this surface with accurate intermolecular potential energy and electric dipole surfaces, the pressure and dielectric second virial coefficients of the complex are calculated by a classical statistical approach. Excellent agreement with experimental results (to within the experimental error bars) is obtained for the pressure second virial coefficient over a range of temperatures. No previous experimental or theoretical investigations have been carried out for the dielectric second virial coefficient, B _ε(T), which is estimated to be about 1.9 cm⁶ mol^− 1 at room temperature. This value results from a balance of terms due to the interaction induced electric dipole polarisability (predominant at high temperatures) and orientational electric dipole contributions.

Keywords:

• interaction induced electric polarisability
• van der Waals complex
• dielectric virial coefficients
• gas virial coefficient
• interaction induced electric dipole

Acknowledgements

This work has been supported by the European Research and Training Network NANOQUANT, contract No. MRTN-CT-2003-506842, and by the Spanish Ministerio de Educación y Ciencia and FEDER (CTQ2005-01076 project) and by Xunta de Galicia and FEDER (Axuda para Consolidación e Estruturación de Unidades de Investigación Competitivas do Sistema Universitario de Galicia 2007/050 and 2007–2013).