It is considered that the lattice sites A and C are partly occupied by the Cu 2+ doped. The d d electron transition spectra in the visible range show that the two deep energy levels of 2.50 eV and 2.64 eV are formed by the Cu 2+ .

• 对于红外反射谱，两对称类的均差别较大，认为Cu2＋部分填充了晶格A位和C位，可见光范围内，d－d电子跃迁谱表明Cu2＋在晶体中形成两个深能级2.；50eV和2