Packing structures and periodic band calculations on DPO (2,5-dipicryl-1,3,4-oxadiazole)

摘要

Molecular mechanics (MM) method with Compass and Dreiding force fields is used to predict molecular packing for DPO among the 7 most possible space groups (P21/C, P-1, P212121, P21, Pbca, C2/C, and Pna21), respectively. Then, periodic band calculations are performed on the predicted crystals using the DFT-GGA-RPBE method. Obtained density of state (DOS) shows that C-O, C-NO2 and N-N bonds are possibly the trigger bond during thermolysis. Band gap (△Eg) equals 1.33 eV, which shows DPO with higher sensitivity. Periodic calculation results are consistent well with that drawn from bond dissociation energy calculations on gas molecule.