IR vibrational assignments for TATB from the density functional B3LYP/6-31G(d) method

Vibrational IR spectra for the 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) have been calculated at density functional B3LYP level using the 6-31G(d) basis set. The effects of isotopic species to the spectra are discussed. The characteristic band at 3322.5 and 3220.9 cm−1 is interpreted as the asymmetrical and symmetrical N-H stretching band, respectively. The band at 1571.3 and 1235.6 cm−1 is attributed to the asymmetrical and symmetrical N-O stretching band, respectively. The bands at 1613.1 and 779.56 cm−1 are attributed to the C-N stretch for the amino groups. The band at 1321.5 cm−1 is attributed to the C-N′ stretch for the nitro groups. Three bands at 1448.4, 1181.2, and 1031.4 cm−1 are assigned to the skeletal stretching modes of the aromatic ring. Three predicted very weak bands at 932.54, 539.32, and 741.48 cm−1 are found without counterparts in the experimental spectrum.