Electron-irradiated (-30C) OH−-doped crystals exhibited a center which absorbed in the region of the Fz center at 380nm. The kinetics of defect formation and destruction suggested that both OH− and Mg2+ impurities had to be present in order to permit its production. An isomorphism between the excitation spectra of this center, and the absorption of H2O− centers in alkali chloride and bromide crystals, suggested that it was of the same nature. That is, it was a so-called wet Fz center, but was more stable; due to intrinsic Mg2+ effects.

[H2O-]z Centers in LiF:OH- Crystals. L.C.Courrol, L.Gomes: Journal of Physics and Chemistry of Solids, 1997, 58[2], 281-6