Application of the electron nuclear dynamics method to hydrogen abstraction and exchange reactions of hydrogen + HOD and deuterium + ammonium ion

The field of quantum molecular dynamics have flourished in the last 20 years. Methods that propose the solution of the time dependent Schrödinger equation for a molecular reactive process abound in the literature. However the majority of these methods focus on solving the nuclear Schrödinger equation subject to a known electronic potential. The electron nuclear dynamics (END) method proposes a framework of a hierarchy of approximations to the Schrödinger equation based on the time dependent variational Principle (TDVP). A general approach is sought to solve the electronic and nuclear problem simultaneously without making use of the Born-Oppenheimer approximation.; The purpose of this work is to apply the minimal END to areas where its unique qualities can give new insight into the relevant dynamics of a chemical or physical process. Minimal END is a method for direct non-adiabatic dynamics. It describes the electrons with a family of complex determinantal wave-functions in terms of non-orthogonal spin orbitals and treats the nuclei as classical particles.; and exchange reactions at hyper-thermal collision energies. We investigate the D₂+$NH+3$ reaction at collision energies ranging from 6 to 16 eV and the H + HOD reaction at a collision energy of 1.575 eV. Collision energies refer to center of mass energies. Emphasis for ground state reactants. In a final application we use minimal END to study the interaction of a strong laser field with the diatomic molecules HF and LiH. Effects of the polarization of the electronic potential on the dynamics are investigated.; Emphasis is also placed on the development of a general method for interpreting the final time dependent wave-function of the product fragments. The purpose is to analyze the final state wave-function in terms of charge transfer channels as well as individual contributions pertaining to excited states.