ISMEAR - Revision history

Schlipf: /* Related tags and articles */

2025-02-27T10:34:02Z

Schlipf at 15:34, 24 February 2025

2025-02-24T15:34:11Z

← Older revision		Revision as of 15:34, 24 February 2025
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	{{TAGDEF\|ISMEAR\|-5 {{!}} -4 {{!}} -3 {{!}} -2 {{!}} -1 {{!}} 0 {{!}} [integer]>0 \|1}}		{{TAGDEF\|ISMEAR\|-15 {{!}} -14 {{!}} -5 {{!}} -4 {{!}} -3 {{!}} -2 {{!}} -1 {{!}} 0 {{!}} [integer]>0 \|1}}

	Description: {{TAG\|ISMEAR}} determines how the partial occupancies ''f''<sub>n'''k'''</sub> are set for each orbital. {{TAG\|SIGMA}} determines the width of the smearing in eV.		Description: {{TAG\|ISMEAR}} determines how the partial occupancies ''f''<sub>n'''k'''</sub> are set for each orbital. {{TAG\|SIGMA}} determines the width of the smearing in eV.

Schlipf: /* Tag options */

2025-02-24T15:32:25Z

Tag options

← Older revision		Revision as of 15:32, 24 February 2025
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	*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.		*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.

			*{{TAGO\|ISMEAR\|-14}}: Tetrahedron method with Fermi-Dirac smearing {{TAG\|SIGMA}}.

			*{{TAGO\|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.\|:}}

Schlipf: /* Tag options */

2025-02-24T10:48:16Z

Tag options

← Older revision		Revision as of 10:48, 24 February 2025
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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}} ~~or {{FILE\|INCAR}} file,~~ and kept fixed throughout run.		*{{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).
	~~:You~~ can also choose occupancies with the ~~tags~~ {{TAG\|FERWE}} and ~~in case of spin-polarized calculations also~~ {{TAG\|FERDO}}.

	*{{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 ==

Schlipf: /* Related tags and articles */

2025-02-24T10:39:25Z

Schlipf at 10:39, 24 February 2025

2025-02-24T10:39:09Z

@@ Line 3: / Line 3: @@
 Description: {{TAG|ISMEAR}} determines how the partial occupancies ''f''<sub>n'''k'''</sub> are set for each orbital. {{TAG|SIGMA}} determines the width of the smearing in eV.
 ----
 == Tag options ==
@@ Line 23: / Line 25: @@
 {{NB|mind|Use a [[KPOINTS|&Gamma;-centered '''k'''-mesh]] for the tetrahedron methods.|:}}
 == Related tags and articles ==
@@ Line 47: / Line 31: @@
 {{TAG|FERDO}},
 {{TAG|SMEARINGS}},
 [[K-point integration]]

Schlipf: /* Tag options */

2025-02-24T10:34:54Z

Tag options

← Older revision		Revision as of 10:34, 24 February 2025
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	== Tag options ==		== Tag options ==
	*{{~~TAG~~\|ISMEAR}} ~~= ''N'' (''N''>0)~~: method of Methfessel-Paxton order ~~''N''~~.
			*{{TAGO\|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.
	*{{~~TAG~~\|ISMEAR}} ~~= −1~~: Fermi smearing.		*{{TAGO\|ISMEAR\|0}}: Gaussian smearing with width {{TAG\|SIGMA}}.
	*{{~~TAG~~\|ISMEAR}} ~~= −2~~: ~~partial~~ occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
			*{{TAGO\|ISMEAR\|-1}}: Fermi smearing with width {{TAG\|SIGMA}}.

			*{{TAGO\|ISMEAR\|-2}}: Partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
	:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.		:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.

	*{{~~TAG~~\|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.

			*{{TAGO\|ISMEAR\|-4}}: Tetrahedron method without smearing.

	*{{~~TAG~~\|ISMEAR}} ~~= −4~~: ~~tetrahedron~~ method ~~(use a [[KPOINTS\|Γ-centered '''k'''-mesh]])~~.		*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.
	*{{~~TAG~~\|~~ISMEAR}} = −5: tetrahedron method with Blöchl corrections (use~~ a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		{{NB\|mind\|Use a [[KPOINTS\|Γ-centered '''k'''-mesh]] for the tetrahedron methods.\|:}}
	~~{{NB\|mind\|{{TAG\|SIGMA}} is ignored~~ for the tetrahedron ~~method~~.\|:}}

	== How to set ISMEAR ==		== How to set ISMEAR ==

Schlipf: /* Tag options */

2025-02-24T10:29:17Z

Tag options

← Older revision		Revision as of 10:29, 24 February 2025
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	== Tag options ==		== Tag options ==
	*{{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, as well as larger than 1. This~~ can yield erroneous results for insulators.		{{NB\|mind\|Methfessel-Paxton can yield erroneous results for insulators because the partial occupancies can be unphysical.\|:}}
	*{{TAG\|ISMEAR}}=0: Gaussian smearing.		*{{TAG\|ISMEAR}} = 0: Gaussian smearing.
	*{{TAG\|ISMEAR}}=−1: Fermi smearing.		*{{TAG\|ISMEAR}} = −1: Fermi smearing.
	*{{TAG\|ISMEAR}}=−2: partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.		*{{TAG\|ISMEAR}} = −2: partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
	:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.		:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.

	*{{TAG\|ISMEAR}}=−3: perform a loop over ~~smearing-parameters supplied in the {{FILE\|INCAR}} file.~~		*{{TAG\|ISMEAR}} = −3: perform a loop over {{TAG\|SMEARINGS}} parameters supplied in the {{FILE\|INCAR}} file.
	~~:In this case a tag~~
	{{TAG\|SMEARINGS}}~~= ismear<sub>1</sub> sigma<sub>1</sub> ismear<sub>2</sub> sigma<sub>2</sub> ...~~
	~~:must be present~~ in the {{FILE\|INCAR}} file, supplying different smearing parameters. {{TAG\|IBRION}} has to be set to -1 and {{TAG\|NSW}} to the number of supplied pairs ismear<sub>i</sub>/sigma<sub>i</sub>. The first loop is done using the tetrahedron method with Blöchl corrections.

	*{{TAG\|ISMEAR}}=−4: tetrahedron method (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		*{{TAG\|ISMEAR}} = −4: tetrahedron method (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).
	*{{TAG\|ISMEAR}}=−5: tetrahedron method with Blöchl corrections (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		*{{TAG\|ISMEAR}} = −5: tetrahedron method with Blöchl corrections (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).
	{{NB\|mind\|{{TAG\|SIGMA}} is ignored for the tetrahedron method.\|:}}		{{NB\|mind\|{{TAG\|SIGMA}} is ignored for the tetrahedron method.\|:}}

Schlipf: /* Tag options */

2025-02-24T10:02:03Z

Tag options

← Older revision		Revision as of 10:02, 24 February 2025
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	*{{TAG\|ISMEAR}}=−1: Fermi smearing.		*{{TAG\|ISMEAR}}=−1: Fermi smearing.
	*{{TAG\|ISMEAR}}=−2: partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.		*{{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~~		:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.
	{{TAG\|FERWE}} ~~= f(1) f(2) f(3) ... f({{TAG\|NBANDS}}×N<sub>'''k'''</sub>)~~
	:and ~~for~~ spin-polarized calculations~~, additionally~~
	{{TAG\|FERDO}} ~~= f(1) f(2) f(3) ... f({{TAG\|NBANDS}}×N<sub>'''k'''</sub>)~~
	: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).

	:The occupancies are even kept fixed during ionic relaxations or molecular dynamics simulations. However, keeping the orbital occupancies fixed, requires that the orbital order does not change during the self-consistency cycle or during the optimization of the orbitals. Imagine, for instance, that the eigenenergy of the 65th orbital moves below the orbital energy of the 64th orbital. Then the subspace diagonalization step will swap both orbitals, but the occupancies will remain as read from the INCAR file (this means that the originally unoccupied 65th orbital will move to the 64th place and it will hence become occupied). This problem can be often circumvented by specifying {{TAG\|LDIAG}}=.FALSE. in the INCAR file.

	~~:Note that the 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: perform a loop over smearing-parameters supplied in the {{FILE\|INCAR}} file.		*{{TAG\|ISMEAR}}=−3: perform a loop over smearing-parameters supplied in the {{FILE\|INCAR}} file.

Wolloch: /* Related tags and articles */

2024-10-22T07:16:15Z

← Older revision		Revision as of 10:34, 27 February 2025
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	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|SIGMA}},		{{TAG\|SIGMA}},
			{{TAG\|EFERMI}},
	{{TAG\|FERWE}},		{{TAG\|FERWE}},
	{{TAG\|FERDO}},		{{TAG\|FERDO}},

← Older revision		Revision as of 15:32, 24 February 2025
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	*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.		*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.

			*{{TAGO\|ISMEAR\|-14}}: Tetrahedron method with Fermi-Dirac smearing {{TAG\|SIGMA}}.

			*{{TAGO\|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.\|:}}

← Older revision		Revision as of 10:48, 24 February 2025
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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}} ~~or {{FILE\|INCAR}} file,~~ and kept fixed throughout run.		*{{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).
	~~:You~~ can also choose occupancies with the ~~tags~~ {{TAG\|FERWE}} and ~~in case of spin-polarized calculations also~~ {{TAG\|FERDO}}.

	*{{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.
Line 24:		Line 23:
	*{{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 ==

← Older revision		Revision as of 10:34, 24 February 2025
Line 5:		Line 5:

	== Tag options ==		== Tag options ==
	*{{~~TAG~~\|ISMEAR}} ~~= ''N'' (''N''>0)~~: method of Methfessel-Paxton order ~~''N''~~.
			*{{TAGO\|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.
	*{{~~TAG~~\|ISMEAR}} ~~= −1~~: Fermi smearing.		*{{TAGO\|ISMEAR\|0}}: Gaussian smearing with width {{TAG\|SIGMA}}.
	*{{~~TAG~~\|ISMEAR}} ~~= −2~~: ~~partial~~ occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
			*{{TAGO\|ISMEAR\|-1}}: Fermi smearing with width {{TAG\|SIGMA}}.

			*{{TAGO\|ISMEAR\|-2}}: Partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
	:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.		:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.

	*{{~~TAG~~\|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.

			*{{TAGO\|ISMEAR\|-4}}: Tetrahedron method without smearing.

	*{{~~TAG~~\|ISMEAR}} ~~= −4~~: ~~tetrahedron~~ method ~~(use a [[KPOINTS\|Γ-centered '''k'''-mesh]])~~.		*{{TAGO\|ISMEAR\|-5}}: Tetrahedron method with Blöchl corrections without smearing.
	*{{~~TAG~~\|~~ISMEAR}} = −5: tetrahedron method with Blöchl corrections (use~~ a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		{{NB\|mind\|Use a [[KPOINTS\|Γ-centered '''k'''-mesh]] for the tetrahedron methods.\|:}}
	~~{{NB\|mind\|{{TAG\|SIGMA}} is ignored~~ for the tetrahedron ~~method~~.\|:}}

	== How to set ISMEAR ==		== How to set ISMEAR ==

← Older revision		Revision as of 10:29, 24 February 2025
Line 5:		Line 5:

	== Tag options ==		== Tag options ==
	*{{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, as well as larger than 1. This~~ can yield erroneous results for insulators.		{{NB\|mind\|Methfessel-Paxton can yield erroneous results for insulators because the partial occupancies can be unphysical.\|:}}
	*{{TAG\|ISMEAR}}=0: Gaussian smearing.		*{{TAG\|ISMEAR}} = 0: Gaussian smearing.
	*{{TAG\|ISMEAR}}=−1: Fermi smearing.		*{{TAG\|ISMEAR}} = −1: Fermi smearing.
	*{{TAG\|ISMEAR}}=−2: partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.		*{{TAG\|ISMEAR}} = −2: partial occupancies are read in from the {{FILE\|WAVECAR}} or {{FILE\|INCAR}} file, and kept fixed throughout run.
	:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.		:You can also choose occupancies with the tags {{TAG\|FERWE}} and in case of spin-polarized calculations also {{TAG\|FERDO}}.

	*{{TAG\|ISMEAR}}=−3: perform a loop over ~~smearing-parameters supplied in the {{FILE\|INCAR}} file.~~		*{{TAG\|ISMEAR}} = −3: perform a loop over {{TAG\|SMEARINGS}} parameters supplied in the {{FILE\|INCAR}} file.
	~~:In this case a tag~~
	{{TAG\|SMEARINGS}}~~= ismear<sub>1</sub> sigma<sub>1</sub> ismear<sub>2</sub> sigma<sub>2</sub> ...~~
	~~:must be present~~ in the {{FILE\|INCAR}} file, supplying different smearing parameters. {{TAG\|IBRION}} has to be set to -1 and {{TAG\|NSW}} to the number of supplied pairs ismear<sub>i</sub>/sigma<sub>i</sub>. The first loop is done using the tetrahedron method with Blöchl corrections.

	*{{TAG\|ISMEAR}}=−4: tetrahedron method (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		*{{TAG\|ISMEAR}} = −4: tetrahedron method (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).
	*{{TAG\|ISMEAR}}=−5: tetrahedron method with Blöchl corrections (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).		*{{TAG\|ISMEAR}} = −5: tetrahedron method with Blöchl corrections (use a [[KPOINTS\|Γ-centered '''k'''-mesh]]).
	{{NB\|mind\|{{TAG\|SIGMA}} is ignored for the tetrahedron method.\|:}}		{{NB\|mind\|{{TAG\|SIGMA}} is ignored for the tetrahedron method.\|:}}

← Older revision		Revision as of 10:39, 24 February 2025
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	{{TAG\|FERDO}},		{{TAG\|FERDO}},
	{{TAG\|SMEARINGS}},		{{TAG\|SMEARINGS}},
	[[Smearing technique]]		[[Smearing technique]],
	[[K-point integration]]		[[K-point integration]]

← Older revision		Revision as of 07:16, 22 October 2024
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	{{TAG\|FERWE}},		{{TAG\|FERWE}},
	{{TAG\|FERDO}},		{{TAG\|FERDO}},
	{{TAG\|SMEARINGS}}		{{TAG\|SMEARINGS}},
			[[K-point integration]]

	{{sc\|ISMEAR\|Examples\|Examples that use this tag}}		{{sc\|ISMEAR\|Examples\|Examples that use this tag}}