AB-INITIO CALCULATIONS OF THE STRUCTURAL, ENERGETIC AND VIBRATIONAL PROPERTIES OF SOME HYDROGEN-BONDED AND VAN-DER-WAALS DIMERS .2. SULFUR-DIOXIDE

The structures of a number of possible dimers of sulphur dioxide have been optimized by means of a series of ab initio molecular orbital cal culations. The relative interaction energies and the numbers of negati ve eigenvalues of each model computed as part of the vibrational analy sis have enabled us to narrow down the number of possibilities for the identity of the most probable dimer structure. The infrared spectra o f the preferred dimers have been predicted, and the results will be us ed as an aid in the analysis and interpretation of the spectra of sulp hur dioxide trapped in nitrogen and argon matrices at cryogenic temper atures, to be reported in a forthcoming paper.