2023 AIChE Annual Meeting
Enabling the Structure-Property Predictions of New Organic Photovoltaic Chemistries with Quantum Chemical Parameterizations
We develop computational tools to fill in force field parameter gaps for molecular dynamics (MD) simulations. Specifically, we focus on high-efficiency organic photovoltaic (OPV) materials Y6 and BTO, which have recently achieved power conversion efficiencies exceeding 17%. We implement the open-source QUBEKit software stack on high-performance computing infrastructure to parameterize molecular fragments, defined using SMILES strings. We examine the structural characteristics of these materials using real and frequency space techniques through MD simulations varying in density and temperature. Our findings reveal the absence of discernible crystal structures or long-range periodicities within these morphologies. Despite their lack of order, these factors suggest that the studied molecules have charge transport capabilities that do not rely on short-range order, setting them apart from many other OPV materials. Additionally, we conduct a comparative assessment of the QUBEKit force field against the established OPLS amber force field, providing insights into their relative suitability for OPV materials simulations.