| Autor: |
Ishii, Takugo, Ogasawara, Kazuyoshi, Adachi, Hirohiko |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 1/8/2002, Vol. 116 Issue 2, p471, 9p, 3 Charts, 8 Graphs |
| Abstrakt: |
The multiplet structures of tetrahedrally and octahedrally oxo-coordinated 3d[sup 2] and 3d[sup 3] transition metals were calculated by the first-principles electronic-structure calculation method for many-electron system. The corresponding notations for the electron configurations, φ[sub d][sup 2] and φ[sub d][sup 3] were proposed to distinguish the present method based on a molecular orbital method from traditional methods based on atomic calculation. The multiplet energies depending on metal–oxygen distances were obtained. The calculated energies of the lowest spin-forbidden states decreased in the order Cr[sup 4+]>Mn[sup 5+]>Fe[sup 6+] in tetrahedrally coordinated φ[sub d][sup 2] metals, on the other hand, those increased in the order Ti[sup 2+]>V[sup 3+] in octahedrally coordinated φ[sub d][sup 2] metals, and V2+3+ in octahedrally coordinated φ[sub d][sup 3] metals. The decreasing tendency in the tetrahedrally coordinated system originated from the strong covalency. On the other hand, the increasing tendency in the octahedrally coordinated systems originated from the correlation-correction effect considered in the method. A stronger nephelauxetic effect was obtained in the tetrahedrally coordinated system than the octahedrally coordinated systems. This originated from the stronger covalency in the tetrahedrally coordinated system, however, the difference between metals was dominated by correlation-correction effect and differences in free ions rather than covalency. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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