Ab initio intermolecular potential energy surfaces of HeCS2, NeCS2 and ArCS2 complexes

作者：Farrokhpour H^*; Tozihi M

来源：Molecular Physics, 2013, 111(6): 779-791.

DOI：10.1080/00268976.2012.745630

• potential energy surface
• HeCS2
• ArCS2
• NeCS2
• CCSD(T)

The potential energy surfaces of the HeCS2, NeCS2 and ArCS2 van der Waals complexes were calculated for the first time at the CCSD(T) level of theory using the aug-cc-pVDZ basis set augmented with a set of midbond functions (3s3p2d1f1g). It was found that the calculated interaction potential, using the applied basis set, readily converges to the complete basis set limit. For a broad range of intermolecular separations and configurations, the interaction energies were obtained by the supermolecular approach with the full counterpoise correction for the basis set superposition error (BSSE). In addition, symmetry-adapted perturbation theory (SAPT) calculations were performed with the same basis set in order to determine the character of the interaction energy of the most stable configuration of each complex at different intermolecular separations in order to make a comparison with the CCSD(T) results. The CCSD(T) calculated potential energy surface of each complex was fitted to an analytic expression to obtain the values of the isotropic dipoledipole () and dipolequadruple () dispersion coefficients of each complex. Finally, the interaction second virial coefficients (B-12) were obtained using the calculated potential energy surface and used together with the experimental second virial coefficients of pure gases (CS2, Ar, Ne and He) to obtain the second virial coefficient of mixtures of CS2 with rare gas at different temperatures and mole fractions.

• 出版日期2013-3-1