Ηλεκτρονιακή δομή των οξειδίων ΜΟ 0, M=Sc, Ti, Cr, Mn, μέσω υπολογισμών πρώτων αρχών

Abstract

Applying the most reliable ab initio techniques, we studied the neutral, positively and negatively singly charged monoxides of four of the first row transition metals, ΜΟ0,± (Μ = Sc, Ti, Cr, Mn). In particular, we employed the multireference configuration interaction and single reference coupled cluster methodologies in conjunction with basis sets of quadruple?ζ quality. Correlating all valence electrons of both atoms, we constructed full potential energy curves of a total of 152 electronic states, providing spectroscopic constants, dissociation energies, bond distances, dipole moments (for the neutral species) and excitation energies for all of them. The inclusion of the 3s23p6 semi?core electrons in the CI procedure, as well as the influence of the scalar relativistic effects were taken into account selectively for some of them. The numerical results of the present study are compared favorably with the available experimental data, whereas they are more accurate and systematic than any other theoretical work in the previous literature. Concerning the electronic structure, the neutral and positive species of the examined oxides exhibit a clear ionic character, Μ+Ο? and Μ2+Ο? respectively, while for the anions the negative charge is located mainly on the oxygen atom, Μ?Ο?.