Fundamentals of Trajectory-Based Methods for Nonadiabatic Dynamics

In this chapter, I outline the fundamental concepts and frameworks used to construct trajectory-based methods of nonadiabatic dynamics simulations. The chapter is organized according to a common anatomy of multiple trajectory-based approaches rather than as a collection of accounts on existing methods. It highlights the natural evolution of the ideas behind these methods and provides glimpses into a more than 30-years history of such developments. Many reported computational schemes are composed of common methodological “building blocks” – the groups of algorithms tailored to various types of calculations involved in computational algorithms. The chapter overviews a wide variety of possibilities to conduct one or another part of such calculations and that can be regarded the methodological “building blocks”.