Dr. Christof Schuette
Konrad-Zuse-Zentrum
Freie University of Berlin
Berlin, Germany

Monday, July 7, 1997
3:00 pm (CT)
3269 Beckman Institute

Abstract

In molecular dynamics applications there is a growing interest in mixed quantum-classical models. This talk is concerned with two of these models: the adiabatic or Born=D0Oppenheimer (BO) model and the so--called QCMD model. Both models describe most atoms of the molecular system by the means of classical mechanics, but an important, small portion of the system by the means of a wave function. In the BO model this wave function is adiabatically coupled to the classical motion while the QCMD model consists of a singularly perturbedSchroedinger equation, nonlinearly coupled to the Newtonian equations. Under certain conditions both models are known to approximate the full quantum dynamical evolution of the system. In contrast to the BO model, the QCMD model and its trajectory bundle version include nonadiabatic processes, e.g., transitions between the energy levels of the quantum system or resonance effects near level crossings.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.