A Density Functional Study of Structures and Vibrations of Ta3O and Ta3O

Density functional calculations of neutral and anionic tantalum trimer monoxide are presented. The calculations were performed employing scalar quasi–relativistic effective core potentials. Different isomers of Ta3O and Ta3O&minus were studied in order to determine the ground state structures. For both systems a planar C2v structure with an edge-bound oxygen atom was found as ground state. Equilibrium structure parameters, harmonic frequencies, adiabatic electron affinity and Kohn-Sham orbital diagrams are reported. The calculated values are in good agreement with the available experimental data obtained from negative ion photoelectron spectroscopy. The correlation diagram between the neutral and anionic Ta3O shows that, in agreement with the experimental prediction, the extra electron in the anionic system occupies a nonbonding orbital.