Shear-strain induced decomposition of 1,1-diamino-2,2-dinitroethylene

The structural and electronic features of shear strains in the molecular crystal 1,1-diamino-2,2-dinitroethylene and their effect on decomposition of the material are investigated. The authors demonstrate that shear strains lower the decomposition barrier and narrow the band gap of the solid and thus facilitate thermal chemistry in molecular materials. The appearance of defect-related electronic states in the band gap is consistent with previous results for dislocation modeling in molecular solids and with experiments on energetic materials. The dynamic behavior of the band gap contains a rich variety of information about the details of the decomposition processes at the initiation stage. (c) 2006 American Institute of Physics.