Molecular Dynamics Simulation and Density Functional Theory Insight into the Cocrystal Explosive of Hexaazaisowurtzitane/Nitroguanidine

Theoretical methods involving molecular dynamics (MD) simulation and density functional theory were performed to investigate the different molecular ratios, mechanical Properties, structure, trigger bond, and intermolecular interaction of hexaazaisowurtzitane (CL-20)/nitroguanidine (NQ) cocrystal explosive. Results of MD simulation show that CL-20 and NQ packed in ratios of 1: 1 present the larger binding energy and better mechanical properties than any other molecular ratios, which indicates 1: 1 cocrystal can form the stable crystal structure. Shorter length and larger dissociation energy of trigger bond in composite structure than in isolated CL-20 component suggests that the cocrystal may exhibit less sensitive than CL-20. Analyses of atoms in molecules, reduced density gradient, and natural bond orbital confirm that intermolecular interactions are mainly derived from a series of weak hydrogen bond and strong vdW forces, involving of NH center dot center dot center dot O, CH center dot center dot center dot O, CH center dot center dot center dot N, O center dot center dot center dot N, and O center dot center dot center dot O. Additionally, composite structures of 2 and 3 bringing us more attractive performance will act as a key role in constructing of CL-20/NQ cocrystal explosive. (C) 2015 Wiley Periodicals, Inc.