title: A molecular dynamics study of 1,1-diamino-2,2-dinitroethylene (FOX-7) crystal using a symmetry adapted perturbation theory-based intermolecular force field.
abstract: A dimer potential energy function for 1,1-diamino-2,2-dinitroethylene (FOX-7) has been developed using symmetry adapted perturbation theory based on a Kohn-Sham density functional theory description of the monomers [SAPT(DFT)]. Interaction energies of 1008 dimer configurations were computed in an augmented double zeta basis set and fitted to an atom-atom intermolecular potential energy function of Coulomb plus Buckingham exp-6 form. The potential was used in isothermal-isostress molecular dynamics simulations to study the structure and thermal/pressure response of FOX-7 crystal. The simulated structure is in very good agreement with experiment and the computed thermal/pressure response of the crystal shows significant anisotropy with respect to crystallographic direction, in-line with experimental observations. It is concluded that SAPT(DFT) is an excellent method for development of intermolecular potentials for energetic molecular crystals.
authors.affiliation: The Army Research Laboratory, Aberdeen Proving Ground, Maryland, 21005, USA. decarlos.taylor@us.army.mil
authors.forename: DeCarlos E
authors.initials: DE
authors.lastname: Taylor
authors.forename: Fazle
authors.initials: F
authors.lastname: Rob
authors.forename: Betsy M
authors.initials: BM
authors.lastname: Rice
authors.forename: Rafal
authors.initials: R
authors.lastname: Podeszwa
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szalewicz
mesh_terms: D018360:Crystallography, X-Ray; D005030:Ethylenes / Q000737:chemistry*; D008958:Models, Molecular; D009574:Nitro Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: C520681:1,1-diamino-2,2-dinitroethylene; D005030:Ethylenes; D009574:Nitro Compounds