Merzuk Kaltak introduces calculating the optical bandgap in VASP. He covers the fundamental theory of the Hartree-Fock method, density functional theory (DFT), and and many-body perturbation theory and how to calculate the optical gap using DFT, the random phase approximation (RPA), and the GW approximation. Finally he introduces strongly correlated systems and methods that can be used to investigate them such as DFT+U and constrained RPA (CRPA).
The lecture of Pedro Melo's that is referred to in the lecture can be watched here: https://youtu.be/3YKJZHmcGhY
0:00:00 Introduction
0:01:13 Overview
0:02:04 Part1: Electronic problem
0:02:59 Hartree-Fock method
0:06:17 Fundamental and optical bandgaps
0:11:04 Part 2: Density functional theory (DFT)
0:11:05 Fundamentals of DFT
0:14:17 Common density functionals
0:22:33 Part 3: Many-body perturbation theory fundamentals
0:23:17 Green’s functions, quasi-particles, and diagrams
0:28:16 GW approximation
0:28:41 Random phase approximation (RPA)
0:32:00 GW and RPA in VASP
0:37:47 Part 4: Strongly correlated systems
0:38:38 DTF+U
0:40:32 Dynamical mean field theory (DMFT) and model Hamiltonians
0:41:39 Constrained RPA (CRPA)
0:45:36 CRPA in VASP
