Electronic Band Properties of CaSr sub 2 Bi sub 2 Cu sub 2 O sub 8.

The electronic structure of body-centered-tetragonal CaSr sub 2 Bi sub 2 Cu sub 2 O sub 8 , an undistorted stoichiometric prototype of the latest high-T sub 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 CuO sub 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%).