Accurate Photochemistry in the Condensed Phase

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Troy Van Voorhis of the Massachusetts Institute of Technology is supported by an award from the Theory, Models and Computational Methods Program to develop, implement and apply transformative tools for modeling photochemical processes in complex environments. In particular, Van Voorhis and his research group focus on extending the techniques of ground state electronic structure theory to the accurate treatment of electronic excited states. They employ these new methods to understand three key photochemical processes: excited state intramolecular electron transfer (ET), ultrafast fluorescence spectroscopy and nonradiative quenching of dyes. They use constrained density functional theory (DFT) as a framework for simulating electron transfer. To describe fluorescence spectra and the dynamic Stokes shift they are developing a hybrid of novel DFT and wave function techniques. The simulations are among the most ambitious studies of condensed phase photochemical dynamics attempted to date. This research is developing a palette of general, widely applicable techniques for the accurate description of photochemistry in solution. The techniques developed in the course of this research are applicable to molecules that play key functional roles in photosynthesis, organic light-emitting diodes (LEDs) and chemical sensing. Researchers around the world will have access to these methods through the Q-Chem package of programs, making the potential impact essentially limitless. Graduate students and postdoctoral associates are being trained in this project. The PI and his group also produce, for a general audience, web-based short films based on their research projects. .