Abstract
The electronic structure of Y1-xPrxBa2Cu3O7 is described by a tight-binding Hamiltonian in which the Pr-O hybridization and the 2pσ-2pπ Coulomb repulsion are taken into account. The dependence of planar hole-density, localized hole-density and chemical potential of holes on Pr concentration is calculated by a coherent potential approximation. The result shows that the insensitivity of hole-density on the CuO3 chains with the Pr-doping is due to the 2pσ-2pπ repulsion. Some other experimental facts can also be well interpreted.