Chalcogen, Lanthanoid, Rare earth, Electronic energy gap, Trigonal

• Co-La-O
• La-Mn-O-Sr
• La-O
• Ba-La-Mn-O
• B-Ce-Lu-O-Pr-Sc
• values of electronic energy gap
• energy gap for indirect transition
• energy gap for direct transition
• thermal energy gap
• polaron formation energy
• lanthanoid
• rare earth
• chalcogen
• transitional