Webinar 45 by Maximilian Menger and Vale Cofer-Shabica: Chemistry doesn't happen in a vacuum: Bringing advanced solvent environments to Q-Chem for dynamics and more


The accurate description of electronic energy relaxation in supramolecular and solvated systems presents a considerable challenge for quantum chemistry. Proper descriptions can only be realized if the environment’s effects on structures and excited states are modeled correctly. Unfortunately, a fully quantum mechanical description of such systems is often infeasible due to their large sizes. However for many systems, the process of interest is localized in a small region, while the majority of the molecular system acts as an embedding environment. In such a case, multi-scale approaches can be applied, which treat the environment and the active region on different footing. Here, we present GIFS a Quantum Mechanics/Molecular Mechanics (QMMM) interface framework between Q-Chem and Gromacs, a fast, free, and extensively developed molecular dynamics (MD) software. It enables the use of QM/MM for simple Born-Oppenheimer MD as well as trajectory surface hopping dynamics. GIFS provides an extensible and efficient way to combine the electronic structure capabilities of Q-Chem with the advanced MD algorithms in Gromacs (or other MD codes). GIFS supports electrostatic (or mechanical) embedding at the QM/MM boundary. Our talk will describe the features of GIFS and provide examples for how the code can be used to study molecular properties in complex environments.