Li4E8 (E = P, As, Sb, Bi) clusters: The quest for realgar-type [E8]4- zintl anions

Abstract

A systematic computational study focused on searching for the global minima and low-lying isomers of the Li4E8 (E = P, As, Sb, Bi) series of clusters is reported. The global-minimum structures of Li4P8, Li4As8, and Li4Sb8 as well as one of the lowest-lying Li4Bi8 isomers were found to contain a realgar-type [E8]4- unit, which is a rare Zintl anion. Increased stability of this skeleton allows its presence to be expected in more complex chemical compounds containing group 15 elements with appropriate stoichiometry. The most probable structures of [E8]4- (E = P, As, Sb, Bi) Zintl anions were predicted by first-principles calculations.