Theoretical studies. To get some more insights into the chemical bonding and main stability factors of the title phase, in particular the applicability of the Zintl-Klemm concept, and to understand the origin of the experimental phase width and In/Zn partial ordering, theoretical investigations were conducted on the idealized stoichiometry Ba8Zn2In3Bi10. The electronic band structure was calculated using LMTO code, the calculated density of states (DOS) is represented in Figure . Ba8Zn2In3Bi10 corresponds to a narrow band gap semiconductor. In on In1, In3, Zn5; Zn on In2, Zn4. The results can be summarized as followed: