Hauptseminar Porous Media SS 2021/ab initio MD

Date

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Time

TBA

Topic

Density functional theory based MD

Speaker

TBD

Tutor

Azade Yazdanyar

Contents

In this topic, we aim to introduce the fundamentals of Density Functional Theory (DFT), which allow us to understand the electronic structure of matter. We will start by discussing Schrödinger's equation. Due to its complexities, 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, Ehrenfest dynamics, and the Car-Parrinello 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
• The electronic structure and Schrödinger's equation
• The Hohenberg-Kohn density functional theory
• The Kohn-Sham ansatz
• The Born-Oppenheimer approximation

Literature

• A bird's-eye view of density-functional theory, K. Capelle, 2002
• The ABC of DFT, K. Burke et al., https://dft.uci.edu/doc/g1.pdf
• Approximate Density Functionals: Which Should I Choose?, D. Rappoport, N.R.M. Crawford, F. Furche, K. and Burke, 2009, In Encyclopedia of Inorganic Chemistry (eds R.B. King, R.H. Crabtree, C.M. Lukehart, D.A. Atwood and R.A. Scott), https://doi.org/10.1002/0470862106.ia615
• Molecular Modelling: Principles and Applications, A. Leach
• Introduction to Computational Chemistry, F. Jensen, Wiley & Sons Ltd