Vibrational frequencies of small selenium molecules

The geometries and vibrational frequencies of Sen clusters (n=2–8) are calculated using ab initio 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 Se6 (D3d) and Se8 (D4d). The calculations provide predictions for future experimental studies.