Additive intermolecular potentials from ab initio calculations: trends in Rg 2 -dihalogen van der Waals trimers

Author： Diez-Pardos Carmen Valdés Alvaro Prosmiti Rita

ISSN： 1432-881X

Source： Theoretical Chemistry Accounts, Vol.118, Iss.3, 2007-09, pp. : 511-517

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Abstract

In the present study, the validity of the pairwise additivity of the interactions, derived from the Rg₂ and Rg-dihalogen CCSD(T) potentials, is investigated by means of ab initio electronic structure and quantum-mechanical calculations. The topology of the potential surfaces of three different types of Rg₂-dihalogen vdW complexes is studied and general trends within the Rg₂-dihalogen family are discussed. Calculations of vibrational energies, including all five intermolecular degrees of freedom, are performed on such pairwise-additive potentials. The results are compared with experimental data from high-resolution spectroscopy, and provide further information on the additivity of the intermolecular forces for the He₂-dihalogen trimers.