Extraction of an alloy of the nominal composition “KSnBi” by an crown-6 melt, and subsequent by 1,2-diaminoethane (en) resulted in the formation of a new ternary Zintl salt [K(crown-6)]2[Sn2Bi2] (1) comprising the known binary anion [Sn2Bi2]2–. Herein we report synthesis and structure of 1, along with a density functional (DFT) study of the anion. The crystal structure of 1 was solved and refined in the cubic space group F23 (no. 196). Unit cell dimensions at 100 K: a = 20.8776(15) Å, V = 9100.0(11) Å3 [R(int) = 0.0467], final R values R1 = 0.0521, [I > 2σ(I)], wR2 = 0.0915 (all data).