Identification of the structure of the 3107 cm⁻¹ H-related defect in diamond

A prominent hydrogen-related infrared absorption peak seen in many types of diamonds at 3107 cm⁻¹ has been the subject of investigation for many years. It is present in natural type-Ia material and can be introduced by heat-treating synthetic or CVD diamond. Based upon the most recent experimental data, it is thought that the defect giving rise to this vibrational mode is vacancy-related and is likely to contain nitrogen. Using first-principles simulations we present a VN₃H model for the originating centre that simultaneously satisfies the different experimental observations including the strain response.