A DFT study of structure and molecular spectroscopy of carbon suboxide

The optimized geometries of molecular carbon suboxide were obtained by usin g B3LYP calculation of density functional theory (DFT) with the 6-31G(d) an d 6-311G(2d) basis sets. The normal vibrational frequencies of the two typi cal configurations were calculated at the B3LYP/6-31G(d) level and the scal ed vibrational frequencies were compared with experiments. A good agreement is obtained between the Computed and experimentally observed properties. T he results show that the molecule C3O2 has a W-shape bent form (C-2 nu symm etry). The calculated bond angles of C-C-C and C-C-O with B3LYP/6-31G(d) ar e 162.3 degrees and 178.8 degrees, respectively.