ARE METAL-CO MOLECULES LINEAR - SCCO, TICO, VCO, AND CRCO CASES STUDIED IN MRCI METHOD COMPARED WITH DFT METHOD

The equilibrium geometries for the low-lying high-spin electronic stat es of ScCO, TiCO, VCO, and CrCO molecules were studies with the ab ini tio method. Restricted Hartree-Fock, multireference configuration inte ractions, and perturbation calculations were done employing flexible b asis sets. We found the equilibrium geometries of the ScCO, TiCO, and VCO molecules to be linear, which is in agreement with a recent densit y functional calculation. In contrast, we found the CrCO molecule line ar while the density functional calculation found it to be bent. As th e CrCO molecule is very weakly bonded, we think that this molecule nee ds further studies with higher-level methods.