Chapter 4 - Advanced ab initio molecular dynamics and coarse-grained molecular dynamics

Abstract

This chapter introduces two classes of advanced molecular dynamics (MD) methods: ab initio MD (AIMD) methods and coarse-grained MD (CGMD) methods. The AIMD methods provide more accurate descriptions of atomic interactions by including electronic degrees of freedom, whereas the CGMD methods expand the temporal and spatial scales of MD simulations by reducing the number of degrees of freedom. The discussion of the AIMD methods begins with the derivation of classical MD from the time-dependent Schrödinger equations of an atomic system. Two typical AIMD methods, namely, the Born–Oppenheimer and Car–Parrinello methods, are then introduced with their respective fundamentals highlighted. For the CGMD methods, three widely adopted bottom-up approaches, namely, the iterative Boltzmann inversion approach, multiscale CG approach, and relative entropy optimization approach, are briefly introduced. The contents in this chapter aim to provide elementary background knowledge of both AIMD and CGMD in a concise manner, which would be useful for further studies in these fields.