The main absorption band of C-center at 1130 cm“ is unusuallyvweak compared to the 1344 cmT' line. It is in contrast with natural and HPHT-grown synthetic diamonds of type lb, where the 1130 cmT' band is two to three times stronger than the 1344 cmT' line, Other spectral features identified as components of C-center and NT-center are at 1290 cm” (C), 1245 cm” (NT), 1125 cm" (C), 1090 cm” (C), and 1045 cm" (NT). A pronounced band with maximum at 828 cm" is probably not related to C and N1’ centers