A Quantum-classical Investigation of Environmental Effects on Electronic Dynamics at Conical Intersections

• Main Author: Kelly, Aaron
• Other Authors: Kapral, Raymond E.
• Language: en_ca
• Published: 2010
• Online Access: http://hdl.handle.net/1807/24783

In this thesis we employ the methods of quantum classical Liouville theory in order to explore the effects of an external environment on electronic dynamics, in systems containing conical intersections. In studying a simple, yet nontrivial, model in the gas phase we find that the short-time dynamics are well approximated by a hybrid MC/MD solution to the QCL equation. Upon including an external environment the population transfer profile changes, based on the various paramter values chosen. Electronic decoherence and the partial/complete destruction of geometric phase effects are also observed. Based on earlier work on master equation dynamics in QCL theory, we find that a Markovian approximation to the dynamics for systems containing conical intersections is not easily justified. In order to access longer time-scale phenomena another, less computationally demanding, solution method was also derived in the mapping basis. This method involves more severe approximations to the QCL equation than the MC/MD method, and as such is not as physically robust, yet still manages to reproduce some important aspects of the dynamics over a picosecond time-scale.