Quantum Chemical Study of Niobium and Tantalum M4O10 Oxide Clusters and M4O10– Anions

Abstract

Structural parameters and vibrational frequencies of the clusters (T_d)–Nb₄O₁₀, (C_3v)-TaNb₃O₁₀, (D_2d)-Nb₄O₁₀^–, and (C_s)-TaNb₃O₁₀^– were calculated. According to the (U)DFT/SDD calculations with BLYP, B3LYP, and PBE0 functionals magnetization of the anion (D_2d)-Nb₄O₁₀^– is distributed equally among four niobium atoms. In the anion (C_s)-TaNb₃O₁₀^– unpaired electron presumably occupies niobium atoms. The distinction in contributions from Nb atoms in the magnetization of the tantalum-containing cluster grows with the exchange component of the DFT functional in the series of functionals BLYP < B3LYP < PBE0 < UHF.