E 43 Electronic structure and chemical bonding in Sr4Nb17O26 / V. M. Zainullina, V. P. Zhukov, V. G. Zubkov, A. P. Tyutyunnik // Journal of Structural Chemistry. - 1998. - Vol. 39, № 5. - P627-635 : il. - Bibliogr. : p. 634-635 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ОКСОНИОБАТ СТРОНЦИЯ -- МЕТОД ЛМТО Аннотация: The electronic structure of oxoniobate Sr4Nb17026 is studied by the linear muffin-tin orbital (LMTO) method. It is shown that the high-energy conduction band consists of the Nb4d states and the hybridized valence band is formed by the Nb4d and 02p states. The band structure of this compound is characterized by superposition of the bands of the 2p states of perovskite oxygen atoms and the 4d states of monoxide niobium atoms. The degree of oxidation of the perovskite and monoxide niobium atoms is + 5 and + 2.56, respectively. Chemical bonding is analyzed using the electron localization function and model Hiickel calculations. The niobium-oxygen bond is shown to be the strongest. The Fermi level is localized in the vicinity of the bottom of the niobium antibonding state band, which explains the existence of Sr4-xNb17026 in the homogeneity region corresponding to 0 < x < 0.3 Полный текст |