Nonhomogeneous charge distribution in layered high-Tc superconductors.
We consider the problem of the charge distribution of holes among the various CuO{sub 2} layers in the unit cell for compounds of the type Tl{sub 2}Ba{sub 2}Ca{sub {ital n}{minus}1}Cu{sub {ital n}}O{sub 2{ital n}+4}. In analogy with graphite intercalation compounds, the charge distribution is strongly nonhomogeneous (for {ital n}{ge}3) with a depletion in the central layers. This result points to a special importance of the bounding layers and it provides a way to understand the observed maximum {ital T}{sub {ital c}} as a function of {ital n}.