E 43 Electronic structure and chemical bonding in yttrium dicarbide and strontium dicarbide / V. P. Zhukov, D. L. Novikov, N. I. Medvedeva, V. A. Gubanov // Journal of Structural Chemistry. - 1989. - Vol. 30, № 4. - P553-559 : il. - Bibliogr. : p. 558-559 (11 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ДИКАРБИД ИТТРИЯ -- ДИКАРБИД СТРОНЦИЯ -- МЕТОД ДИСКРЕТНОГО ВАРЬИРОВАНИЯ Аннотация: The energy band structure of yttrium dicarbide and strontium dicarbide has been investigated by the nonempirical LMTO band method and the Xalfa-discrete-variation cluster method. Calculations have been performed by the Xalfa-DV method for cluster models with the formulas (Y6C2) 10+ and (Sr6C2)10+ and contour maps of the molecular orbitals of the clusters have been constructed. The results of the calculations have been used to analyze the chemical bonding and some physicochemical properties. It has been shown that the bonding between the C2(2-) grouping and the neighboring yttrium and strontium atoms is effected mainly by a 4dY, 2pC group orbital, which appears in the composition of the band of the metallic states. An expansion for the instability of the crystal structure of SrC 2 has been given Полный текст |