Chapter Three - Time-Dependent Treatment of Molecular Processes

A time-dependent treatment of molecular processes is presented that emphasizes the importance of a dynamical treatment of participating electrons and starts from a choice of molecular Lagrangian. The ingredients of such a theoretical and computational approach include the choice of coordinate system and its effect on the molecular Hamiltonian. Also the choice of molecular wave function is essential, and the particular role of the time-dependent parameters that originate in a coherent state representation is discussed. The simplest form of Electron Nuclear Dynamics is presented, and many of its applications are discussed with reference to the publications where they are originally presented. The challenges of rendering such dynamics are mentioned in the final section.