ORDER IN THE ATOMIC DISTRIBUTION OF COORDINATION SPHERES IN PEROVSKITE-RELATED OXIDES

The order in the atomic distribution for coordinational spheres around the arbitrarily chosen center points is an important characteristic o f crystal lattices. A sufficiently simple algorithm for the determinat ion of the space distribution of the neighbors of any atom in the crys tal lattice is presented. It is shown that the packing of coordination al spheres may be represented by one of seven regular and semiregular polyhedrons or their combinations. It is suggested that special sampli ng functions can determine the order in the atomic distribution for co ordinational spheres in any monoatomic and polyatomic crystal lattice. The method is presented for the dielectrics NaCl and CsCl, for exampl e, CaF2 and perovskite BaTiO3. (C) 1998 Elsevier Science B.V. All righ ts reserved.