(687c) Validating a New Force Field and Extensible Analysis for a Large-Scale Screening Study of P3HT

Validating computational studies is challenging because (a) identical reproduction of a previously-used software and hardware may not be possible, (b) assumptions used during modeling and analysis may not be documented or clearly communicated, and (c) the computational effort for doing so may be prohibitive. Here we demonstrate an example validation study of the organic semiconducting polymer P3HT enabled by MoSDeF tools. We specify the software stack using docker containers and conda environment files. We document model, simulation input, and analysis details using the MoSDeF tools Foyer, mBuild, and Freud. We define a simulation state space using signac, and use signac-flow to manage submission of jobs to HPC clusters. We perform molecular dynamics simulations using HOOMD-Blue replicating the state space sampled in prior P3HT work with ~400 GPU-hours of computational effort, using GAFF-UA in place of the OPLS-UA force field. We validate the use of GAFF-UA in this work, observing that order-disorder transition temperature and scattering patterns follow the same dependence on solvent quality seen with OPLS-UA. We conclude with a discussion of additional work making structural analysis more transparent, reproducible, usable by others, and extensible (TRUE) with the GRiTS package we develop.