ISPIN: Difference between revisions
Adding more details for spin polarization calculations |
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Description: {{TAG|ISPIN}} specifies whether a calculation is performed with or without spin polarization. | Description: {{TAG|ISPIN}} specifies whether a calculation is performed with or without spin polarization. | ||
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In spin-polarized calculations, VASP treats spin-up and spin-down electrons separately, allowing each spin channel to develop a different charge density and occupation. This is essential for magnetic systems; for nonmagnetic systems it is generally unnecessary and increases computational cost. | |||
*{{TAG|ISPIN}}=1: VASP performs a non-spin-polarized calculation. Spin-up and spin-down electrons share a single charge density. | |||
*{{TAG|ISPIN}}=2: VASP performs a spin-polarized collinear calculation. Spin-up and spin-down electrons are treated separately. | |||
*{{TAG|ISPIN}}=2: spin-polarized collinear | |||
Spin-polarized calculations are commonly used for magnetic materials such as Fe, Co, Ni, and magnetic oxides. To initialize magnetic moments on atoms, combine {{TAG|ISPIN}}=2 with {{TAG|MAGMOM}}. | Spin-polarized calculations are commonly used for magnetic materials such as Fe, Co, Ni, and magnetic oxides. To initialize magnetic moments on atoms, combine {{TAG|ISPIN}}=2 with {{TAG|MAGMOM}}. | ||
ISPIN = 2 | |||
ISPIN = 2 | MAGMOM = 2*5.0 2*-5.0 | ||
MAGMOM = 2*5.0 2*-5.0 | |||
This example initializes two atoms with positive magnetic moments and two atoms with negative magnetic moments, which may be useful for antiferromagnetic calculations. | This example initializes two atoms with positive magnetic moments and two atoms with negative magnetic moments, which may be useful for antiferromagnetic calculations. | ||
{{NB| | {{NB|mind|For noncollinear calculations, {{TAG|ISPIN}} is ignored; use {{TAG|LNONCOLLINEAR}}{{=}}.TRUE. instead.|:}} | ||
{{NB|mind|Since VASP 6.5.0, the calculation exits with an error if {{TAG|ISPIN}}{{=}}2 and {{TAG|MAGMOM}} are used together with {{TAG|LNONCOLLINEAR}}{{=}}.TRUE.|:}} | |||
== Related tags and articles == | == Related tags and articles == | ||
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{{TAG|LNONCOLLINEAR}} | {{TAG|LNONCOLLINEAR}} | ||
{{sc|ISPIN| | {{sc|ISPIN|Howto|Examples that use this tag}} | ||
[[Category:INCAR tag]][[Category:Magnetism]] | [[Category:INCAR tag]][[Category:Magnetism]] | ||
Latest revision as of 14:20, 1 June 2026
ISPIN = 1 | 2
Default: ISPIN = 1
Description: ISPIN specifies whether a calculation is performed with or without spin polarization.
In spin-polarized calculations, VASP treats spin-up and spin-down electrons separately, allowing each spin channel to develop a different charge density and occupation. This is essential for magnetic systems; for nonmagnetic systems it is generally unnecessary and increases computational cost.
- ISPIN=1: VASP performs a non-spin-polarized calculation. Spin-up and spin-down electrons share a single charge density.
- ISPIN=2: VASP performs a spin-polarized collinear calculation. Spin-up and spin-down electrons are treated separately.
Spin-polarized calculations are commonly used for magnetic materials such as Fe, Co, Ni, and magnetic oxides. To initialize magnetic moments on atoms, combine ISPIN=2 with MAGMOM.
ISPIN = 2 MAGMOM = 2*5.0 2*-5.0
This example initializes two atoms with positive magnetic moments and two atoms with negative magnetic moments, which may be useful for antiferromagnetic calculations.
Mind: For noncollinear calculations, ISPIN is ignored; use LNONCOLLINEAR=.TRUE. instead.
Mind: Since VASP 6.5.0, the calculation exits with an error if ISPIN=2 and MAGMOM are used together with LNONCOLLINEAR=.TRUE.