Anubhab Haldar
  • Member for 1 year, 8 months
  • Last seen more than a week ago
Difficult cases for converging Kohn-Sham SCF calculations
13 votes

A few materials/simulation boxes I've had some proper trouble with: HSE06 + noncollinear magnetism + antiferromagnetism, Vasp noncollinear: This was a strongly antiferro material (4 Fe atoms, in an ...

View answer
How to generate the high symmetry paths for band structure calculations?
12 votes

If the crystal unit cell is in a format readable by ASE, then you can use code that looks approximately like so: from ase.io import read atoms = read("myfilename.xyz") bandpath = atoms.cell....

View answer
How does the mBJ potential give an accurate band gap as compared to LDA and GGA?
11 votes

Model potentials for exchange: Exchange-correlation potentials like mBJ and GLLBSC have model orbital-dependent corrections included in the form of the functional. I'll first try to get the ...

View answer
What are the pitfalls of calculating band gaps via density functional theory?
Accepted answer
9 votes

The important thing to keep in mind is that the Kohn-Sham (KS) band gap is not the fundamental/quasiparticle gap. Even theoretically. This is not an 'underestimation' of the band gap. They are not the ...

View answer
VASP GW PAW Pseudopotentials
Accepted answer
8 votes

A lot of it will be in the difference in cost. But as a rule of thumb, GW potentials are typically harder, and include more states (semicores). This need not always be the case, since if you look at ...

View answer
KS-DFT versus G0W0
Accepted answer
8 votes

I am going to try to go systematically through your question and answer the critical bits. I may edit this answer going forward as I'm able to express my thoughts better or people point out important ...

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

The GPAW code can do GW/BSE and it uses purely PAW potentials. So it's absolutely possible to do GW/BSE with PAW sets. The involvement for the implementation, however, is another topic. From Kevin J. ...

View answer
Can we do anything to reduce the number of displacements in a frozen phonon lattice dynamics study?
5 votes

ProfM's answer gets the core idea perfectly right: Symmetry really is your best friend here. However, symmetry analysis is often quite involved, especially for larger unit cells. I recently ...

View answer
How to calculate the Berry connection difference?
3 votes

Perhaps not the most detailed answer, since I'm not hugely familiar with the precise functionality/details that would be involved, but GPAW does seem to have the functionality. Caveat: The GPAW docs ...

View answer
How do you model quantum-confinement effects in optically active (e.g. plasmonic) mesoscopic structures?
Accepted answer
3 votes

How do you model quantum-confinement effects in optically active (e.g. plasmonic) mesoscopic structures? There should be a Comsol module that corresponds to this work, since it's mentioned that they ...

View answer