QUANTUM-CHEMICAL STUDIES OF MOLECULAR DIFLUORIDES AND DICHLORIDES OF BERYLLIUM AND MAGNESIUM

Geometry and vibrational frequencies have been calculated for monomers , dimers and selected oligomers of BeF2, BeCl2, MgF2, and MgCl2. The f it to experimental structure-where available-is good, and fit to exper imental frequencies suggests that all dimers have the expected D-2h sy mmetry. All title halides seem to be able to form D-2d ring chain trim ers, which is verified for MgF2 and MgCl2 by comparing with experiment al IR spectre. Calculations on BeCl2 oligomers up to the decamer are i ncluded. For all compounds, HF/6-31 + G seem to give frequencies with sufficient accuracy after scaling with consistent scaling factors. (C ) 1998 Elsevier Science B.V. All rights reserved.