Chalcogen, Disordered, Metal, Electronic energy gap, Trigonal

• Bi-Fe-O
• Bi-Te
• Bi-Se
• S-Ti
• Fe-O
• values of electronic energy gap
• energy gap for direct transition
• energy gap for indirect transition
• thermal energy gap
• polaron formation energy
• disordered
• chalcogen
• metal
• transitional
• conductor