  Using the Hubbard Hamiltonian for transition metal-3d and oxygen-2p states
with perovskite geometry, we propose a new scaling procedure for a nontrivial
extension of these systems to large spatial dimensions $D$. The scaling
procedure is based on a selective treatment of different hopping processes for
large $D$ and can not be generated by a unique scaling of the hopping element.
The model is solved in the limit $D \rightarrow \infty$ by the iterated
perturbation theory and using an extended non-crossing approximation. We
discuss the evolution of quasi particles at the Fermi-level upon doping,
leading to interesting insight into the dynamical character of the charge
carriers near the metal insulator instability of transition metal oxide
systems, three dimensional perovskites and other strongly correlated transition
metal oxides.
