Illustration 3 Transition Metal Monoxides with Edge-Sharing Octahedra

3 Illustration 3 Transition Metal Monoxides with Edge-Sharing Octahedra 

Now look at the transition metal monoxides with the rock-salt stmcture. Since the rock-salt structure is a three-dimensional network of edge-sharing MX(, octahedra, in which the metal may possess an incomplete d shell, it can be concluded that the Fermi level should reside in the metal t2g- or -block bands. 

the and p Bloch sum interactions are not symmetry allowed. Nor is the hybridization between the d and py Bloch sums. The d orbital at the origin does, however, have a tt antibonding interaction with the axial p orbitals (not shown) directly above and below it. In other words, the d orbital at the origin only interacts with two of the six first-nearest neighbor oxygen atoms. 

A = oo) for the d z Bioch sum (ieft) and Bioch sum in a singie piane viewed down [0 01]. 

At W(kx = lir/a, ky = tt/o, k = 0),X = a along the x axis and 2a along the y axis. The net d-d interaction is antibonding. None of the d-p interactions are symmetry allowed. In moving from Wto X, the dx2-yi band may be either nondispersive or slightly raised in energy. The actual bandwidth will depend on the strength of the M 3d-M 3d interactions in comparison to the M 3d-0 2p interactions. 

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