Beyond Perovskites: Quantum Luminescence from Bulk Cs4PbBr6 Single Crystals, Michele De Bastiani; Ibrahim Dursun; Buthainah Alshankiti; Xiao-He Miao; Jun Yin; Emre Yengel; Erkki Alarousu; Bekir Turedi; Yuhai Zhang; Jawaher Almutlaq; Makhsud Saidaminov; Somak Mitra; Iman Roqan; Jean-luc Bredas; Omar Mohammed; Osman Bakr, submitted to ACS Chemistry of Materials, 29, 7108–7113 (2017)