Abstract
The semiempirical HFD model of intermolecular forces is extended to strongly anisotropic atom-diatom systems. A single-centre representation of the dispersion energy is found to be inadequate, and a method of partitioning dispersion forces between two centres of attraction is developed, based on the A tensor of the diatomic molecule. The method is tested on the systems Ar-HCl and Ar-HF, for which accurate data sensitive to the potential anisotropy are available, and gives promising results. The quality of the SCF potential used is crucial, and it appears that for Ar-HCl the results are limited by deficiencies in the SCF potentials available. For Ar-HF, the dispersion coefficients are not well known, and the HFD method provides a single-parameter functional form capable of reproducing all the available data.
Original language | English |
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Pages (from-to) | 763-782 |
Number of pages | 20 |
Journal | Molecular Physics |
Volume | 52 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1984 |
Externally published | Yes |