Hauptseminar Porous Media SS 2021/ab initio MD
- Density functional theory based MD
- Konstantin Nikolaou
- Azade Yazdanyar
In this topic, we aim to introduce the fundamentals of Density Functional Theory (DFT), which allows us to understand the electronic structure of matter. We will start by discussing Schrödinger's equation. Due to its complexity, Schrödinger's equation can only be analytically solved for very simple systems or with rigorous simplifications.
We will then discuss the foundations of DFT, first introduced by Hohenberg, Kohn and Sham. DFT uses the electron density to describe the energy state of the system, and is much simpler to obtain than the many-body wavefunction.
A development on DFT was to generalize it further for dynamic systems. Therefore, one can use first-principles electronic structure methods 'on the fly' to obtain the forces, and couple it with a time-step evolution formulation. There exist various approaches to ab initio MD (AIMD), such as the Born-Oppenheimer MD. These topics will be marginally presented.
This is the first talk from a three-part series. To adhere to a consistent theme, the discussion will mainly revolve around the potential energy surface.
Main points to be discussed
- The many-body problem, electronic structure and Schrödinger's equation
- The Hohenberg-Kohn density functional theory
- The Kohn-Sham ansatz
- Ab initio MD
- Strengths and limitations of DFT and AIMD