Citation: McCall, Kyle M.; Stoumpos, Constantinos C.; Kostina, Svetlana S.; Kanatzidis, Mercouri G.; Wessels, Bruce W. (2017). Strong Electron--Phonon Coupling and Self-Trapped Excitons in the Defect Halide Perovskites A3M2I9 (A = Cs, Rb; M = Bi, Sb). Chemistry of Materials, , pp. -.