Vibrational frequencies of small selenium molecules

The geometries and vibrational frequencies of Se(n) clusters (n = 2-8) are calculated using abinitio molecular orbital theory at various levels of approximation. The computed vibrational frequencies are in satisfactory agreement with the available experimental data on matrix isolated clusters and have small systematic deviations with IR and Raman spectra of crystalline Sr(6) (D(3d)) and Se(8) (D(4d)). The calculations provide predictions for future experimental studies. (C) 1998 Elsevier Science B.V. All rights reserved.