Chalcogen, Rare earth, Energy level diagram, Monoclinic

• Er-La-O-V-Yb
• Er-O-Si-Tm-Y-Yb
• Er-O-W-Y
• Al-Eu-O-Sr
• Er-O-W-Y-Yb
• chalcogen
• rare earth
• lanthanoid
• luminescent
• transitional