Alan Aspuru-Guzik of Harvard University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to develop time dependent density functional (TDDFT) methods for open systems. This award is co-funded by the Condensed Matter and Materials Theory program in the Division of Materials Research. New theoretical methods are required to explain the timescales of energy and electron transport in chemical systems, such as photosynthesis and organic photovoltaics. In order to allow for dissipation and relaxation, the quantum system must be allowed to exchange energy with an infinite bath. In this project, Aspuru-Guzik and his coworkers develop first-principles theories of dissipative electronic dynamics in molecules based on basic physics, rather than input parameters. The project differs from previous work by the level of detail provided for the model of the electronic system. These new approaches treat the combined system in a rigorous manner. Computer simulation codes developed alongside these theories are applied to chemical problems like excitonic transport.
This research allows for the study of quantum dynamics of systems of relevance to light harvesting by plants and solar cells made of organic materials. The methods we develop could answer fundamental questions about the details of these processes from an atomistic perspective. A diverse group of researchers are engaged in this project. The program codes developed by the group will be incorporated into publicly available open-source quantum chemistry packages. The PI is also involved in a distributed effort called "The Clean Energy Project"; thousands of computer users from around the world donate their idle computing power to search for new materials for solar cells.
