Electronic band properties of CaSr2Bi2Cu2O8

Abstract

The electronic structure of body-centered tetragonal ${\mathrm{CaSr}}_2$ ${\mathrm{Bi}}_2$ ${\mathrm{Cu}}_2$ ${\mathrm{O}}_8$, an undistorted stoichiometric prototype of the latest high-$T_c$ superconducting cuprate, has been calculated with the use of the linear augmented-plane-wave method. The overall results are similar to those of the earlier cuprates, exhibiting band characteristics that are strongly two dimensional. The new compound features pairs of conducting BiO and ${\mathrm{CuO}}_2$ planes in which the lowest pair of antibonding Bi(6p)-O(2p) bands are slightly (∼4%) occupied and the corresponding pair of planar Cu(3d)-O(2p) bands are less than half filled (∼46%).