The response of structure and vibrational modes of 1, 3-diamino-2, 4, 6-trinitrobenzene (DATB) to pressure

To investigate the dependence of corresponding parameters with pressure, the first-principles calculations were implemented to study the physical and chemical evolutions of DATB. The breakpoint of lattice parameters, bond length and angle, vibrational modes, interaction and band gap is observed at 2 GPa, which is close to the discontinuity observed in the experiment around 5 Gpa. The calculational parameters are consistent with the available data, which verifies the reliability of our calculation. Since the compression, the intermolecular arrangement is more steeper and further causing the breakpoint around 2 GPa, which can be attributed to the variation in the hydorgen bonds structrue and no phase transition observed here.