Abstract
Modified orbital occupation and inhomogeneous charge distribution in high-T-c oxide compounds due to doping and/or defects play a huge role for the material properties. To establish insight into the charge redistribution, we address metallic YBa2Cu3O7 in two prototypical configurations: Ca doped (hole doping) and O deficient (electron doping). By means of first principles calculations for fully relaxed structures, we evaluate the orbital occupations. We find that the change of the charge density, in particular in the CuO2 planes, shows a complex spatial pattern instead of the expected uniform (de-) population of the valence states. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729892]