DENSITY FUNCTIONAL CALCULATION OF THE ELECTRONIC STRUCTURES OF SOME A(5)B(6)C(7)-TYPE CRYSTALS

The electronic band structures of some A(5)B(6)C(7)-type ternary compounds, BiSeI, BiSI, BiSCl, BiSBr, BiSeBr and SbSeBr, are investigated using the density functional theory and pseudopotential theory under the generalized gradient approximation (GGA). The electronic band structures obtained show that these crystals, except for BiSeI, have an indirect band gap.