Density functional tight binding calculations for the simulation of shocked nitromethane with LATTE-LAMMPS

Abstract

We investigate a density functional tight binding (DFTB) approach to the modeling of atomic interactions by looking at the energetics of phenol and nitromethane isomers. Taking advantage of the interfacing of the LATTE DFTB and LAMMPS molecular dynamics codes, we then perform nudged elastic band calculations to determine isomerization reaction barriers, and Hugoniostat calculations of shocked nitromethane. Our DFTB parameterization (DFTB–lanl) provides an accurate description of the energetics of organic molecules, and yields Hugoniot curves that are in reasonable agreement with experiments and calibrated equations of state.