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materialsproject / pymatgen

Python Materials Genomics (pymatgen) is a robust materials analysis code that defines classes for structures and molecules with support for many electronic structure codes. It powers the Materials Project.
https://pymatgen.org
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[Question] Why do we set SIGMA in INCAR for MPRelaxSet when ISMEAR is -5? #4004

Closed DanielYang59 closed 3 weeks ago

DanielYang59 commented 3 weeks ago

Summary

Why do we set SIGMA in INCAR for MPRelaxSet when ISMEAR is -5 (SIGMA would be ignored in this case)? Is it going to be corrected by #3322?

Mind: SIGMA is ignored for the tetrahedron method.

https://github.com/materialsproject/pymatgen/blob/6427b556ea82f364ff4b619dfbcdf7fd7169cce7/src/pymatgen/io/vasp/MPRelaxSet.yaml#L11 https://github.com/materialsproject/pymatgen/blob/6427b556ea82f364ff4b619dfbcdf7fd7169cce7/src/pymatgen/io/vasp/MPRelaxSet.yaml#L80

shyuep commented 3 weeks ago

Because it doesn't matter whether it was set if ISMEAR=-5? And if we set SIGMA to 0, then 0.05 is the default value we use.

DanielYang59 commented 3 weeks ago

Thanks for the reply!

Because it doesn't matter whether it was set if ISMEAR=-5?

Sounds like it might be better to exclude SIGMA for tetrahedron method and include it later when required to avoid confusion. But anyway, we get the same results.