Efthimios Kaxiras received a PhD in theoretical condensed matter physics from MIT and joined
the faculty of Harvard University in 1991. He is the Founding Director of the Institute for
Applied Computational Science, served as the Director of the Initiative on Innovative
Computing, and his distinctions include Fellow of the American Physical Society and Chartered
Physicist of the Institute of Physics. His research interests encompass a wide range of topics in
the physics of solids and fluids, with recent emphasis on materials for renewable energy,
especially batteries and photovoltaics, and on simulations of blood flow in coronary arteries.
The time evolution of a system consisting of electrons and ions often treats electrons in their instantaneous ground state, which cannot capture many interesting processes such as chemical processes that involve excitations, as in reactions at surfaces and charge transport in macromolecules. We will present a methodology based on time-dependent density functional theory for electrons, and classical (Ehrenfest) dynamics for the ions, that successfully captures such processes. We will give a review of key features of the method and several applications. These illustrate how the atomic and electronic structure evolution unravels the elementary steps that constitute a chemical reaction.