Crystal structure and bonding characteristics of In-doped β-Zn4Sb3

► The indium impurity preferentially substitutes one of Sb atoms in Sb-Sb dimer at the 12c Sb(2) site. ► The occupancy of Zn increases by the In substitution for Sb, whereas that of Sb keeps constant. ► The binding energy of Sb 3d shifts to low value. ► The charge transfer occurs from In and Zn to Sb.