title: A coarse-grain force field for RDX: Density dependent and energy conserving.
abstract: We describe the development of a density-dependent transferable coarse-grain model of crystalline hexahydro-1,3,5-trinitro-s-triazine (RDX) that can be used with the energy conserving dissipative particle dynamics method. The model is an extension of a recently reported one-site model of RDX that was developed by using a force-matching method. The density-dependent forces in that original model are provided through an interpolation scheme that poorly conserves energy. The development of the new model presented in this work first involved a multi-objective procedure to improve the structural and thermodynamic properties of the previous model, followed by the inclusion of the density dependency via a conservative form of the force field that conserves energy. The new model accurately predicts the density, structure, pressure-volume isotherm, bulk modulus, and elastic constants of the RDX crystal at ambient pressure and exhibits transferability to a liquid phase at melt conditions.
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Moore
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Barnes
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: Sergei
authors.initials: S
authors.lastname: Izvekov
authors.affiliation: Laboratory of Aerosols Chemistry and Physics, Institute of Chemical Process Fundamentals of the Czech Academy of Sciences, v. v. i., 165 02 Prague 6-Suchdol, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Lísal
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sellers
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: DeCarlos E
authors.initials: DE
authors.lastname: Taylor
authors.affiliation: Energetic Materials Science Branch, RDRL-WML-B, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Brennan