A theoretical study of the curves for Ta + CO interaction

Potential energy curves for the low-lying electronic states of the TaCO complex have been studied using the complete active space multiconfiguration self-consistent-field method followed by multireference configuration interaction calculations. The nature of chemical bond formation in the different states is discussed. We find two nearly degenerate electronic statesfor TaCO although at the highest level of theory, the 4Δ state prevails.