Chalcogen, Lanthanoid, Luminescent, Rare earth, Energy level diagram

• Al-Ce-O-Y
• Er-O-Y-Yb
• Er-O-Y
• Er-La-O-V-Yb
• Eu-O-P-Sr
• rare earth
• chalcogen
• lanthanoid
• luminescent
• transitional
• tetragonal
• cubic
• orthorhombic
• monoclinic
• trigonal