Alkaline, Chalcogen, Non-disordered, Energy gap for direct transition

• Mg-O
• O-Sr-Ti
• Ba-Cu-F-O-Y
• Mg-O-Zn
• Be-Se
• non-disordered
• alkaline
• chalcogen
• conductor
• semiconductor
• cubic
• orthorhombic
• tetragonal
• monoclinic
• hexagonal