Quasi-particles of a 2D system

MoS2 monolayer (top and side views). Gray: Mo atoms, yellow: S atoms.]]

In this tutorial you will compute the quasiparticle corrections to the band structure of a free-standing single layer of MoS2. Aim of the tutorial is to learn how to efficiently run a GW simulation in a 2D material based on:

• Acceleration techniques of GW in 2D systems
• Parallelization techniques

In the end, you will obtain a quasiparticle band structure based on the simulations, the first step towards the reproduction of an ARPES spectrum. Beware: we won’t use fully converged parameters, so the final result should not be considered very accurate.

Step 1: Initialization

The first step would be as usual to perform a non-self-consistent DFT calculation of MoS2 (using for example Quantum ESPRESSO). Here, you can directly download the QE files from [1]. Once completed the extraction, move inside the 00_QE-DFT folder and then convert QE data into a convenient format for Yambo. Just as a reminder, to convert, run the p2y executable to generate the uninitialised SAVE .

cd 00_QE-DFT/mos2.save
p2y

Now, we need to run the initialization step. Every Yambo run **must** start with this step. Just type

yambo