DFT Study of Nonlinear CS2 Isomers in Singlet and Triplet States

The geometrical optimizations on nonlinear CS2 in the singlet and triplet states have been made using two Density Function Theory（DFT）methods（B3LYP and B3PW91）with 6-311+G* and aug-cc-pVTZ basis sets. Three Singlet states 1A1 and five triplet states（3A2、3B1 and 3B2）have been found，and the frequency analysis confirms that there are no image frequencies for these states，indicating that they are geniune minima at the potential energy surface. At their respective equilibrium geometries，the lowest-lying electronic states are predicted to have an energy ordering by 4t 3B2