Questions tagged [gw-bse]

Questions about the GW approximation or the Bethe-Salpeter Equation (BSE).

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6
votes
1answer
75 views

VASP GW PAW Pseudopotentials

What is the difference between the GW and non-GW potentials in VASP. While it is clear that the GW potentials should be used with GW calculations, the documentation also states that these potentials ...
4
votes
1answer
124 views

VASP GW+SOC band structure calculations

How may I carry out GW+SOC a band structure calculation using VASP? Could anyone familiar describe it step-by-step? I could not find any info regarding this on the VASP wiki.
10
votes
1answer
104 views

KS-DFT versus G0W0

The central equation that KS-DFT will solve is: $$\tag{1}\left[ -\dfrac{1}{2}\nabla^2+V_{ext}+V_{hartree}+V_{xc} \right]\psi_i(\vec{r})=E_i\psi_i(\vec{r})$$ Here $V_{xc}$ is approximated with LDA or ...
8
votes
2answers
144 views

How to plot exciton wave function with phase information?

In GW-BSE calculations, people could analyze the exciton wave function $|S\rangle$ by plotting the BSE eigenvector $A_{cv\mathbf{k}}$ that satisfies $|S\rangle = \sum_{cv\mathbf{k}}A_{cv\mathbf{k}}|cv\...
8
votes
1answer
84 views

How to evaluate the exciton velocity?

I have calculated the exciton wave functions using the GW-BSE method: $$\tag{1}|S\rangle = \sum_{cv\mathbf{k}} A_{cv\mathbf{k}} |cv\mathbf{k}\rangle$$ where $c$ for conduction and $v$ for valence ...
7
votes
0answers
42 views

Recommended code to do XAS/XES/RIXS calculations with?

I am a grad student looking to simulate several XAS/XES and potentially RIXS spectra for some strongly correlated metal-oxides. The materials in question will likely require solving the Bethe-Salpeter ...
12
votes
0answers
98 views

What are the recent developments of GW@BSE to simulate the excited properties of materials?

A twin question related to the TDDFT method is asked in another post. But any comparisons between both methods in recent developments are welcome. The time-dependent density functional theory (TDDFT) ...
17
votes
0answers
123 views

What are the recent developments of TDDFT to simulate the excited properties of materials?

The time-dependent density functional theory (TDDFT) and the many-body perturbation method (GW@BSE) are considered as the two most popular and successful methods to describe the excited-stated ...
5
votes
1answer
169 views

BSE and IQP oscillator strength from VASP

Recently I am trying to calculate the BSE and IQP transition dipole based on VASP lecture on BSE and BSE fatband. However, I have a few questions regarding the BSE and IQP oscillator strength. From ...
10
votes
1answer
156 views

Is there a software that has implemented forces of BSE calculations for solids?

I'd like to investigate the structural relaxations of the excited state for periodic systems. It seems BSE is a practical method that has already been implemented in many codes for static calculations....
10
votes
1answer
150 views

What's the meaning of absorbance in the absorption spectrum calculated by the GW-BSE method?

Q1: As shown in the previous figure, what's the physical meaning of absorbance (y-axis) in the absorption spectrum calculated with the GW-BSE method? Q2: Here the absorbance for the absorption onset $...
19
votes
2answers
294 views

What methods are available for excited state calculations in solids?

In the spirit of a succint answer (3 paragraphs maximum) to create a useful resource, what are the types of excited state calculation available for solids? Please add to the list: Quasiparticle ...
23
votes
3answers
1k views

Given that Kohn-Sham DFT is strictly a ground-state method (at 0 K), how is it sufficient to describe materials in real-life applications?

Kohn-Sham DFT appears to be so popular even though it is strictly a ground-state method - all calculations are done at 0 K. How then, is it so popular when describing materials that have real-life ...
15
votes
1answer
189 views

Can GW-BSE quasiparticle calculations only be run on norm-conserving pseudopotentials (NCPPs)? If so, why not?

I've read in some texts that GW-BSE quasiparticle calculations have only been implemented on Norm-conserving Pseudopotentials (and not Ultra-soft or PAW PPs). Is there a conceptual reason for this? I ...