Alkaline, Transitional, Energy gap for direct transition

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