ISMEAR: Difference between revisions
Tag: Manual revert |
No edit summary |
||
| Line 8: | Line 8: | ||
== Tag options == | == Tag options == | ||
*{{ | *{{TAG|ISMEAR|0|op=>}}: method of Methfessel-Paxton order {{TAG|ISMEAR}} with width {{TAG|SIGMA}}. | ||
{{NB|mind|Methfessel-Paxton can yield erroneous results for insulators because the partial occupancies can be unphysical.|:}} | {{NB|mind|Methfessel-Paxton can yield erroneous results for insulators because the partial occupancies can be unphysical.|:}} | ||
*{{ | *{{TAG|ISMEAR|0}}: Gaussian smearing with width {{TAG|SIGMA}}. | ||
*{{ | *{{TAG|ISMEAR|-1}}: Fermi smearing with width {{TAG|SIGMA}}. | ||
*{{ | *{{TAG|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 {{TAG|ISPIN|2}} calculations). | ||
*{{ | *{{TAG|ISMEAR|-3}}: perform a loop over {{TAG|SMEARINGS}} parameters supplied in the {{FILE|INCAR}} file. | ||
*{{ | *{{TAG|ISMEAR|-4}}: Tetrahedron method without smearing. | ||
*{{ | *{{TAG|ISMEAR|-5}}: Tetrahedron method with Blöchl corrections without smearing. | ||
*{{ | *{{TAG|ISMEAR|-14}}: Tetrahedron method with Fermi-Dirac smearing {{TAG|SIGMA}}. | ||
*{{ | *{{TAG|ISMEAR|-15}}: Tetrahedron method with Blöchl corrections with Fermi-Dirac smearing {{TAG|SIGMA}}. | ||
{{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.|:}} | ||
Latest revision as of 07:45, 24 October 2025
ISMEAR = -15 | -14 | -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, EFERMI, FERWE, FERDO, SMEARINGS, Smearing technique, K-point integration