KBa₂InAs₃ with Coexisting Monomers of [In₂As₇]^13- and Their One-Dimensional Polymers

The title compound was made by fusion of a stoichiometric mixture of the pure elements. The structure (orthorhombic, Cmc2₁, Z = 16, a = 10.129(2) Å, b = 25.208(4) Å, c = 13.884(3) Å) is made of isolated units of [In₂As₇]^13- and a polymer chain of [In₂As₅]^7- made of the same units. According to magnetic measurement, KBa₂InAs₃ is a closed-shell compound, a Zintl phase.