4 ENERGETICALLY LOW-LYING STATES OF SIC2

Ab initio studies and vibrational analysis are reported for the four i somers of the molecule SiC2. The molecule has been optimized at the SC F level of theory using split valence basis sets 3-21G, 3-21G and 6-3 1G. Huzinaga-Dunning double-zeta basis sets have also been used for th e optimization. The computed structural parameters and properties have been compared with the experimental ones. The chemical hardness and c hemical potential have been computed for the four isomers using densit y functional theory. The vibrational frequencies are obtained in 3-21G and 3-21G basis sets.