Antimony triiodide is the chemical compound with the formula SbI₃. This ruby-red solid is the only characterized "binary" iodide of antimony, i.e. the sole compound isolated with the formula Sb_xI_y. It contains antimony in its +3 oxidation state. Like many iodides of the heavier main group elements, its structure depends on the phase. Gaseous SbI₃ is a molecular, pyramidal species as anticipated by VSEPR theory. In the solid state, however, the Sb center is surrounded by an octahedron of six iodide ligands, three of which are closer and three more distant. For the related compound BiI₃, all six Bi—I distances are equal.