Features of the valence electron charge distribution in (LiBXV)-X-II crystals

Total, difference, and deformation electron densities are calculated from the first principles using the density functional theory and the sublattice method for LiBX (B = Mg, Ca, Zn; X = N, P, As) crystals with the sphalerite structure. The nature and formation features of the chemical bonding caused by a change in the chemical composition are revealed. A weak bond between Li+ ions with X anions enables their displacements in the space between crystal-forming tetrahedral (BX)(-) groups. It is found that Ca-X bonds are mainly ionic and in a series of crystals the ionic covalent Li-B bond is traced