In the search for the homogeneity range of Cu6Zn2Sb2, two compounds, Cu5Zn3Sb2 and Cu5.5Zn2.5Sb2, were explored. It was established that Zn selectively chooses the Cu-site of the Cu2Sb (2c) sub-unit to partially substitute, but the Cu-site in the CuZn subunit (4f) remains unaffected (Fig. ). To explain this, Mulliken and Löwdin population analysis on each atom of the parent compound (Cu6Zn2Sb2) was performed. Cu1 seats at the center of a nearly perfect octahedron, surrounded by five Sb and one Zn atom; and it possesses an average Mulliken charge of +0.27; whereas Cu2 seats at the center of a distorted cube of 4 Zn, 2 Sb, and 2 Cu atoms (Fig. ); possesses average Mulliken charge +0.10. Now, Zn, being less electronegative than Cu, prefers the site with more positive charge. Thus, by using the simple electronegativity analogy, the site preference of Zn can be explained (Table ). The same electronegativity analogy doesn't apply to explain the same for the γ-brass compounds in the Cu-Zn system, rather the contributions of the orbital energies come into play, and more complex electronic structures were observed .