LUNAR: Automated input generation and analysis for reactive LAMMPS simulations input and output files

Generating molecular models for the LAMMPS molecular dynamics (MD)
simulation software package is a difficult task and is an impediment to
the more widespread and efficient use of MD in materials design and
development. Fixed-bond force fields generally require manual assignment
of atom types, bonded interactions, charges, and simulation domain sizes.
A new LAMMPS pre- and post-processing toolkit (LUNAR) is presented that
efficiently builds molecular systems for LAMMPS. LUNAR automatically
assigns atom types, generates bonded interactions, assigns charges, and
provides initial configuration methods to generate large molecular
systems. LUNAR can also incorporate chemical reactivity into simulations
using fixed-bond force fields by facilitating the use of the REACTER
protocol. Additionally, LUNAR provides post-processing for free volume
calculations, cure characterization calculations, and property predictions
from LAMMPS thermodynamic outputs. LUNAR has been validated via building
and simulation of pure epoxy and cyanate ester polymer systems with a
comparison of the corresponding predicted structures and properties to
benchmark values, including experimental results from the literature.
LUNAR provides the tools for the computationally-driven development of
next-generation composite materials in the Integrated Computational
Materials Engineering (ICME) and Materials Genome Initiative (MGI)
frameworks.