Hauptseminar Porous Media SS 2021/ab initio MD

Date

2021-05-14

Time

14:30

Topic

Density functional theory based MD

Speaker

Konstantin Nikolaou

Tutor

Azade Yazdanyar

Contents

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

Literature

• A. D. Becke.
  Perspective: Fifty years of density-functional theory in chemical physics.
  The Journal of Chemical Physics 140(18):18A301, 2014.
  [DOI]
• Nathan Argaman, Guy Makov.
  Density functional theory: An introduction.
  American Journal of Physics 68(1):69-79, 2000.
  [DOI]
• Mark E Tuckerman.
  Ab initio molecular dynamics: basic concepts, current trends and novel applications.
  Journal of Physics: Condensed Matter 14(50):R1297–R1355, 2002.
  [DOI]
• Frank Jensen.
  Introduction to Computational Chemistry.
  Edition 2.
  Wiley-VCH Verlag GmbH, 2006. ISBN: 978-0-470-01187-4.
  [PDF] (728 KB)