Doubts about whether nscf is required for liquid water.

[datieniuyyds]

Hello@pinchen xie, I want to calculate the wannier center of the liquid water system. Do I need to perform non-self-consistent calculations? If so, how should I set the k-path of liquid water? grateful!

[PabloPiaggi]

@salinelake this question is addressed to you. I am tagging you so you get the notification. Thanks.

[salinelake]

https://github.com/CSIprinceton/workshop-july-2022/tree/main/hands-on-sessions/day-2/4-deep-wannier/wannier90_example gives an example of the workflow. To avoid glitches from the Wannier90 side, it is better to perform NSCF calculation after a successful SCF calculation. The choice of K-points depends on the system and should be figured out by studying the convergence of physical properties of the system.

[datieniuyyds]

Thank you for your patient answer. There is another question about k-path. Because my system is liquid water. There is no high symmetry point in liquid water. Does the setting of k-points only need to be consistent with the self-consistent one? Gratitude!

[salinelake]

For both crystalline and non-crystalline structures, the Monkhorst-Pack grids are usually adopted for sampling the Brillouin zone.

The setting of k-points in NSCF calculation does not to be exactly the same as it is in the SCF calculation. Usually, the k-points are denser in NSCF calculation to gain more accurate results on electronic structures. You may consult more general tutorials for quantum espresso or VASP for the subtleties here.

[datieniuyyds]

Thank you very much for your patience, salinelake. Your answer helped me a lot. Thank you, PabloPiaggi.