Cluster structures multi-element clusters

Polyoxometalates (POMs) are discrete molecular structures composed of metal cations bridged by oxide anions. They are not multi-metal species with metal-metal bonding, one conventional definition of clusters, but they are clusters in the generic sense of the word. A number of general reviews on POMs have appeared in recent years.1-13 Since a great majority of these structures are anionic, and thus salts with obligatory cations, and constituted primarily of early-transition-metal (d-block) elements in their highest oxidation states, the... 

Due to the muffin-tin approximation of the local multi-centre potential, the applicability of the scattered-wave (SW) method is limited to relatively small and high-symmetry clusters and molecules. On the other hand, it is the prerequisite for generalizing the in-out integration scheme of atomic one-electron wavefiinctions to the multi-centre case. This approach furnishes the multi-centre electronic structure in a particular atom sphere in its single-centre representation. Thus atomic transition-matrix elements can be readily rescaled in terms of near-nucleus electron amplitudes. 

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