The H1 center was characterized by electron spin resonance in monocrystalline diamond, grown by chemical vapor deposition. The results were consistent with a model in which one H atom was trapped at a neutral vacancy-like defect of near-trigonal symmetry.

Symmetry of the Hydrogen-Vacancy-Like Defect H1 in Diamond. K.Iakoubovskii, A.Stesmans, K.Suzuki, A.Sawabe, T.Yamada: Physical Review B, 2002, 66[11], 113203 (3pp)