Mathematical and Numerical Aspects of Quantum Dynamics

Nuclear quantum effects in electronic (non)adiabatic dynamics 

Giovanni Ciccotti

Sapienza University of Rome


Quantum-classical approaches to excited-state dynamics are promising simulation techniques to describe the response of excited molecular systems. They provide a description of the coupled dynamics of electrons and nuclei, based on approximations to the quantum-mechanical problem that allow controlled access to systems of growing complexity. In the design of those approximations, particular care has to be taken in describing the coupling between electronic and nuclear motion, and in accounting for the quantum features of the problem in a realistic way. In this talk we build on the approach introduced by H.Gross and Coll. in the framework of the exact factorization of the electron-nuclear wavefunction, focusing on the coupled-trajectory, mixed quantum-classical (CT-MQC) algorithm recently, developed by F.Agostini and Coll. to solve the exact-factorization equations, introducing a new procedure to efficiently include quantum nuclear effects in the original CT-MQC. The procedure is tested on a very simple model system in two different nonadiabatic regimes. *Work done in collaboration with Federica Agostini & Ivano Tavernelli