ISMEAR: Difference between revisions
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*{{TAGO|ISMEAR|-1}}: Fermi smearing with width {{TAG|SIGMA}}. | *{{TAGO|ISMEAR|-1}}: Fermi smearing with width {{TAG|SIGMA}}. | ||
*{{TAGO|ISMEAR|-2}}: Partial occupancies are read in from the {{FILE|WAVECAR}} | *{{TAGO|ISMEAR|-2}}: Partial occupancies are read in from the {{FILE|WAVECAR}} and kept fixed throughout run. Alternatively, you can also choose occupancies in the {{FILE|INCAR}} file with the tag {{TAG|FERWE}} (and {{TAG|FERDO}} for {{TAGO|ISPIN|2}} calculations). | ||
*{{TAGO|ISMEAR|-3}}: perform a loop over {{TAG|SMEARINGS}} parameters supplied in the {{FILE|INCAR}} file. | *{{TAGO|ISMEAR|-3}}: perform a loop over {{TAG|SMEARINGS}} parameters supplied in the {{FILE|INCAR}} file. | ||
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*{{TAGO|ISMEAR|-5}}: Tetrahedron method with Blöchl corrections without smearing. | *{{TAGO|ISMEAR|-5}}: Tetrahedron method with Blöchl corrections without smearing. | ||
{{NB|mind|Use a [[KPOINTS|Γ-centered '''k'''-mesh]] for the tetrahedron methods.|:}} | {{NB|mind|Use a [[KPOINTS|Γ-centered '''k'''-mesh]] for the tetrahedron methods.|:}} | ||
== Related tags and articles == | == Related tags and articles == | ||
Revision as of 10:48, 24 February 2025
ISMEAR = -5 | -4 | -3 | -2 | -1 | 0 | [integer]>0
Default: ISMEAR = 1
Description: ISMEAR determines how the partial occupancies fnk are set for each orbital. SIGMA determines the width of the smearing in eV.
Please consider how-to guide to choose the optimal smearing technique.
Tag options
Mind: Methfessel-Paxton can yield erroneous results for insulators because the partial occupancies can be unphysical.
ISMEAR = -2: Partial occupancies are read in from the WAVECAR and kept fixed throughout run. Alternatively, you can also choose occupancies in the INCAR file with the tag FERWE (and FERDO forISPIN = 2calculations).
ISMEAR = -4: Tetrahedron method without smearing.
ISMEAR = -5: Tetrahedron method with Blöchl corrections without smearing.
Mind: Use a Γ-centered k-mesh for the tetrahedron methods.
Related tags and articles
SIGMA, FERWE, FERDO, SMEARINGS, Smearing technique, K-point integration