ISMEAR: Difference between revisions

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*{{TAG|ISMEAR}}=''N'' (''N''>0): method of Methfessel-Paxton order ''N''.
*{{TAG|ISMEAR}}=''N'' (''N''>0): method of Methfessel-Paxton order ''N''.
:'''Mind''': For the Methfessel-Paxton scheme the partial occupancies can be negative.
:'''Mind''': For the Methfessel-Paxton scheme the partial occupancies can be negative.
*{{TAG|ISMEAR}}=0:  
*{{TAG|ISMEAR}}=0: Gaussian smearing.
*{{TAG|ISMEAR}}=−1:
*{{TAG|ISMEAR}}=−1: Fermi smearing.
*{{TAG|ISMEAR}}=−2:
*{{TAG|ISMEAR}}=−2:partial occupancies are read in from the {{FILE|WAVECAR}} or {{FILE|INCAR}} file, and kept fixed throughout run.
:To set the occupancies specify
  {{TAG|FERWE}} = f1 f2 f3 ... f({{TAG|NBANDS}})
:and for spin-polarized calculations, additionally
  {{TAG|FERDO}} = f1 f2 f3 ... f({{TAG|NBANDS}})
:in the {{TAG|INCAR}} file. The (partial) occupancies must be specified for all bands and k-points. The band-index runs fastest. The occupancies must be between 0 and 1 (for spin-polarized and non-spin-polarized calculations).
 
:'''Mind''': Partial occupancies are also written to the {{FILE|OUTCAR}} file, but in this case they are multiplied by 2, i.e. they are between 0 and 2.
 
*{{TAG|ISMEAR}}=−3:
*{{TAG|ISMEAR}}=−3:
*{{TAG|ISMEAR}}=−4:
*{{TAG|ISMEAR}}=−4:

Revision as of 16:12, 23 May 2011

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.


  • ISMEAR=N (N>0): method of Methfessel-Paxton order N.
Mind: For the Methfessel-Paxton scheme the partial occupancies can be negative.
  • ISMEAR=0: Gaussian smearing.
  • ISMEAR=−1: Fermi smearing.
  • ISMEAR=−2:partial occupancies are read in from the WAVECAR or INCAR file, and kept fixed throughout run.
To set the occupancies specify
 FERWE = f1 f2 f3 ... f(NBANDS)
and for spin-polarized calculations, additionally
 FERDO = f1 f2 f3 ... f(NBANDS)
in the INCAR file. The (partial) occupancies must be specified for all bands and k-points. The band-index runs fastest. The occupancies must be between 0 and 1 (for spin-polarized and non-spin-polarized calculations).
Mind: Partial occupancies are also written to the OUTCAR file, but in this case they are multiplied by 2, i.e. they are between 0 and 2.

Related Tags and Sections

SIGMA


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