Atoms and molecules are quantum mechanical particles and this is reflected in how they interact, either with each other or with light. Clearly understanding how these interactions occur is fundamental to understanding chemistry. In this talk, an overview will be given of how individual molecules interact and how the outcome of these can be observed experimentally, with emphasis being given to the use of light in initiating and following a reaction. This is the field of femto (and now atto) chemistry. In order to describe these experiments theoretically require quantum molecular dynamics simulations and the basic ideas of these will be presented. This requires solving the time-dependent Schrödinger equation to follow the time-evolution of a wavepacket representing the nuclei moving over potential energy surfaces due to the electrons. For photo-excited reactions, however, the Born-Oppenheimer approximation that provides this picture breaks down and the coupling between the electronic and nuclear motion needs to be considered. This, known as non-adiabatic coupling, often dominates reactions. Recent examples will be given showing our present directions of research and capabilities in studying these theoretically challenging systems.
Graham Worth is Professor of Computational Chemistry. Research in his group focuses on the development of a quantum dynamics computer program to simulate fundamental molecular reactivity, with a particular interest in photo-excited reactions and non-adiabatic effects. He is a main developer of the Quantics software package for quantum dynamics simulations, based on the powerful multi-configuration time-dependent Hartree method. He moved to UCL in 2016. Before this, he worked at the University of Birmingham from 2005 -2016 (research fellow, senior lecturer, professor) and at King's College London 2000 – 2005 (research fellow, lecturer). Prior to that he was a Marie-Curie Fellow, and then a Research Assistant, at the University of Heidelberg in the group of Professor Lenz Cederbaum (1992 – 2000), and a Research Fellow at the EMBL, Heidelberg in the group of Professor Rebecca Wade (1992). He did his DPhil in the group of Professor Graham Richards at the University of Oxford.
Seminar Series by the NYU-ECNU Center for Computational Chemistry at NYU Shanghai