SAXIS - Revision history

Wolloch at 12:33, 12 November 2025

2025-11-12T12:33:05Z

← Older revision		Revision as of 12:33, 12 November 2025
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	The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.		The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.
	{{NB\|warning\|'''SAXIS''' ≠ 0 0 1, is not supported for Hartree-Fock calculations and hybrid functionals ('''LHFCALC''' {{=}} .TRUE.)! These methods set '''ISYM''' {{=}} 3, which only works with the default '''SAXIS'''. You can still use '''SAXIS''' with '''ISYM''' {{=}} -1.}, but in most cases it is computationally more efficient to change '''MAGMOM''' instead.}		{{NB\|warning\|'''SAXIS''' ≠ 0 0 1, is not supported for Hartree-Fock calculations and hybrid functionals ('''LHFCALC''' {{=}} .TRUE.)! These methods set '''ISYM''' {{=}} 3, which only works with the default '''SAXIS'''. You can still use '''SAXIS''' with '''ISYM''' {{=}} -1., but in most cases it is computationally more efficient to change '''MAGMOM''' instead.}}

	== Coordinate system ==		== Coordinate system ==

Wolloch at 12:32, 12 November 2025

2025-11-12T12:32:45Z

← Older revision		Revision as of 12:32, 12 November 2025
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	The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.		The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.
	{{NB\|warning\|'''SAXIS''' ≠ 0 0 1, is not supported for Hartree-Fock calculations and hybrid functionals ('''LHFCALC''' {{=}} .TRUE.)! These methods set '''ISYM''' {{=}} 3, which only works with the default '''SAXIS'''.}}		{{NB\|warning\|'''SAXIS''' ≠ 0 0 1, is not supported for Hartree-Fock calculations and hybrid functionals ('''LHFCALC''' {{=}} .TRUE.)! These methods set '''ISYM''' {{=}} 3, which only works with the default '''SAXIS'''. You can still use '''SAXIS''' with '''ISYM''' {{=}} -1.}, but in most cases it is computationally more efficient to change '''MAGMOM''' instead.}

	== Coordinate system ==		== Coordinate system ==

Wolloch at 09:54, 10 November 2025

2025-11-10T09:54:52Z

← Older revision		Revision as of 09:54, 10 November 2025
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	such that <math>\sigma_3=\mathbf{s}/\|\mathbf{s}\|</math>, i.e., <math>\sigma_3</math> points along <math>\mathbf{s}=(s_x,s_y,s_z)^T</math>. The directions of <math>\sigma_1</math> and <math>\sigma_2</math> are a consequence of rotating <math>\sigma_3</math> to point along <math>\mathbf{s}</math> as described below.		such that <math>\sigma_3=\mathbf{s}/\|\mathbf{s}\|</math>, i.e., <math>\sigma_3</math> points along <math>\mathbf{s}=(s_x,s_y,s_z)^T</math>. The directions of <math>\sigma_1</math> and <math>\sigma_2</math> are a consequence of rotating <math>\sigma_3</math> to point along <math>\mathbf{s}</math> as described below.

	The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.		The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.
			{{NB\|warning\|'''SAXIS''' ≠ 0 0 1, is not supported for Hartree-Fock calculations and hybrid functionals ('''LHFCALC''' {{=}} .TRUE.)! These methods set '''ISYM''' {{=}} 3, which only works with the default '''SAXIS'''.}}

	== Coordinate system ==		== Coordinate system ==

Huebsch at 09:55, 21 September 2023

2023-09-21T09:55:03Z

← Older revision		Revision as of 09:55, 21 September 2023
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	\end{matrix}\right).		\end{matrix}\right).
	</math>		</math>
	{{NB\|mind\|Apply the proper basis transformation when comparing vector-like quantities ~~with~~ spinor-like quantities.\|}}		{{NB\|mind\|Apply the proper basis transformation when comparing vector-like quantities and spinor-like quantities.\|}}
	For instance, when {{TAG\|LORBMOM}}=True the orbital angular momentum is written to the {{FILE\|OUTCAR}} file in Cartesian coordinates. Thus, when comparing the orbital angular momentum (vector-like quantity) and the magnetization (spinor-like quantity), one has to perform a basis transformation on one of the quantities unless the bases agree (default).		For instance, when {{TAG\|LORBMOM}}=True the orbital angular momentum is written to the {{FILE\|OUTCAR}} file in Cartesian coordinates. Thus, when comparing the orbital angular momentum (vector-like quantity) and the magnetization (spinor-like quantity), one has to perform a basis transformation on one of the quantities unless the bases agree (default).

Huebsch at 09:52, 21 September 2023

2023-09-21T09:52:17Z

← Older revision		Revision as of 09:52, 21 September 2023
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	{{TAG\|SAXIS}} = 1 1 0 ! alpha=pi/4, beta=pi/2		{{TAG\|SAXIS}} = 1 1 0 ! alpha=pi/4, beta=pi/2
	:the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math> will be rotated with respect to real space <math>\{\hat x, \hat y, \hat z\} </math> as shown in Fig. 2.		:the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math> will be rotated with respect to real space <math>\{\hat x, \hat y, \hat z\} </math> as shown in Fig. 2.

	<!---		<!---
	The second method also allows to read a preexisting {{FILE\|WAVECAR}} file (from a collinear or non collinear run), and to continue the calculation with a different spin orientation. When a non collinear {{FILE\|WAVECAR}} file is read, the spin is assumed to be parallel to {{TAG\|SAXIS}} (hence VASP will initially report a magnetic moment in the ''z''-direction only).		The second method also allows to read a preexisting {{FILE\|WAVECAR}} file (from a collinear or non collinear run), and to continue the calculation with a different spin orientation. When a non collinear {{FILE\|WAVECAR}} file is read, the spin is assumed to be parallel to {{TAG\|SAXIS}} (hence VASP will initially report a magnetic moment in the ''z''-direction only).
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	VASP reads in the {{FILE\|WAVECAR}} and {{FILE\|CHGCAR}} files, aligns the spin quantization axis parallel to {{TAG\|SAXIS}}, which implies that the magnetic field is now parallel to {{TAG\|SAXIS}}, and performs a non selfconsistent calculation. By comparing the energies for different orientations the magnetic anisotropy can be determined. Please mind, that a completely selfconsistent calculation ({{TAG\|ICHARG}} = 1) is in principle also possible with VASP, but this would allow the spinor wavefunctions to rotate from their initial orientation parallel to {{TAG\|SAXIS}} until the correct groundstate is obtained, i.e. until the magnetic moment is parallel to the easy axis. In practice this rotation will be slow, however, since reorientation of the spin gains little energy. Therefore if the convergence criterion is not too tight, sensible results might be obtained even for fully selfconsistent calculations (in the few cases we have tried this worked beautifully).		VASP reads in the {{FILE\|WAVECAR}} and {{FILE\|CHGCAR}} files, aligns the spin quantization axis parallel to {{TAG\|SAXIS}}, which implies that the magnetic field is now parallel to {{TAG\|SAXIS}}, and performs a non selfconsistent calculation. By comparing the energies for different orientations the magnetic anisotropy can be determined. Please mind, that a completely selfconsistent calculation ({{TAG\|ICHARG}} = 1) is in principle also possible with VASP, but this would allow the spinor wavefunctions to rotate from their initial orientation parallel to {{TAG\|SAXIS}} until the correct groundstate is obtained, i.e. until the magnetic moment is parallel to the easy axis. In practice this rotation will be slow, however, since reorientation of the spin gains little energy. Therefore if the convergence criterion is not too tight, sensible results might be obtained even for fully selfconsistent calculations (in the few cases we have tried this worked beautifully).
	---!>		--->
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|LNONCOLLINEAR}},		{{TAG\|LNONCOLLINEAR}},

Huebsch at 09:50, 21 September 2023

2023-09-21T09:50:57Z

← Older revision		Revision as of 09:50, 21 September 2023
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	{{TAG\|SAXIS}} = s<sub>x</sub> s<sub>y</sub> s<sub>z</sub> ! global spin-quantization axis		{{TAG\|SAXIS}} = s<sub>x</sub> s<sub>y</sub> s<sub>z</sub> ! global spin-quantization axis
	such that <math>\sigma_3=\mathbf{s}/\|\mathbf{s}\|</math>, i.e., <math>\sigma_3</math> points along <math>\mathbf{s}=(s_x,s_y,s_z)</math>. The ~~direction~~ of <math>\sigma_1</math> and <math>\sigma_2</math> is a consequence of rotating <math>\sigma_3</math> to point along <math>\mathbf{s}</math> as described below. The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True).		such that <math>\sigma_3=\mathbf{s}/\|\mathbf{s}\|</math>, i.e., <math>\sigma_3</math> points along <math>\mathbf{s}=(s_x,s_y,s_z)^T</math>. The directions of <math>\sigma_1</math> and <math>\sigma_2</math> are a consequence of rotating <math>\sigma_3</math> to point along <math>\mathbf{s}</math> as described below.

			The relative orientation of spinor space with respect to real space becomes important in case spin-orbit coupling is included ({{TAG\|LSORBIT}}=True). All magnetic moments and spinor-like quantities written or read by VASP are given in the basis of the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.

	== Coordinate system ==		== Coordinate system ==

	~~All magnetic moments and spinor~~-~~like quantities written or read by VASP are given in the basis of the spinor space~~ <math>\~~{\sigma_1~~</math>, <math>\~~sigma_2~~</math>, <math>\mathbf{~~\sigma}_3\~~}</math>. This includes the {{TAG\|MAGMOM}} tag in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file.		[[File:Saxis-angles.png\|300px\|thumb\|Fig 1. Euler angles <math>\alpha</math> and <math>\beta</math> defined by <math>\mathbf{s}=(s_x,s_y,s_z)^T</math>.]]

	The default orientation is <math>\sigma_1=\hat x</math>, <math>\sigma_2 =\hat y</math>, <math>\sigma_3 = \hat z</math>.		The default orientation is <math>\sigma_1=\hat x</math>, <math>\sigma_2 =\hat y</math>, <math>\sigma_3 = \hat z</math>.
	To set <math>\hat{\sigma}_3=s/\|s\|</math>, VASP applies two rotations with Euler angles		To set <math>\hat{\sigma}_3=s/\|s\|</math>, VASP applies two rotations with Euler angles

	:<math>		:<math>
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	\beta&=\arctan2\left(\frac{\sqrt{s_x^2+s_y^2}}{s_z}\right) \in [0,\pi].		\beta&=\arctan2\left(\frac{\sqrt{s_x^2+s_y^2}}{s_z}\right) \in [0,\pi].
	\end{align}		\end{align}
	:</math>		</math>
	Here, <math>\alpha</math> is the angle between the projection of {{TAG\|SAXIS}} onto the ''xy''-plane (s<sub>x</sub>,s<sub>y</sub>,0) and the Cartesian vector <math>\hat x</math>, and <math>\beta</math> is the angle between the vector {{TAG\|SAXIS}} and the Cartesian vector <math>\hat z</math>. Search for `Euler angles` in the {{FILE\|OUTCAR}} file to see what VASP uses. For the default <math>\mathbf{s}=(0,0,1)</math>, <math>\alpha=0</math> and <math>\beta=0</math>.		Here, <math>\alpha</math> is the angle between the projection of {{TAG\|SAXIS}} onto the ''xy'' plane (s<sub>x</sub>,s<sub>y</sub>,0) and the Cartesian vector <math>\hat x</math>, and <math>\beta</math> is the angle between the vector {{TAG\|SAXIS}} and the Cartesian vector <math>\hat z</math>, see Fig. 1. Search for `Euler angles` in the {{FILE\|OUTCAR}} file to see what VASP uses. For the default <math>\mathbf{s}=(0,0,1)</math>, <math>\alpha=0</math> and <math>\beta=0</math>.

	The transformation of a vector <math>\mathbf{m}=(m_1,m_2,m_3)^T</math> given in the basis <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math> into <math>\mathbf{m}'=(m_x,m_y,m_z)^T</math> in Cartesian coordinates and its inverse transformation read		The transformation of a vector <math>\mathbf{m}=(m_1,m_2,m_3)^T</math> given in the basis <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math> into <math>\mathbf{m}'=(m_x,m_y,m_z)^T</math> in Cartesian coordinates and its inverse transformation read
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	\end{matrix}\right).		\end{matrix}\right).
	</math>		</math>

	{{NB\|mind\|Apply the proper basis transformation when comparing vector-like quantities with spinor-like quantities.\|}}		{{NB\|mind\|Apply the proper basis transformation when comparing vector-like quantities with spinor-like quantities.\|}}
	For instance, when {{TAG\|LORBMOM}}=True the orbital angular momentum is written to the {{FILE\|OUTCAR}} file in Cartesian coordinates. Thus, when comparing the orbital angular momentum (vector-like quantity) and the magnetization (spinor-like quantity), one has to perform a basis transformation on one of the quantities unless the bases agree (default).		For instance, when {{TAG\|LORBMOM}}=True the orbital angular momentum is written to the {{FILE\|OUTCAR}} file in Cartesian coordinates. Thus, when comparing the orbital angular momentum (vector-like quantity) and the magnetization (spinor-like quantity), one has to perform a basis transformation on one of the quantities unless the bases agree (default).
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	== Example ==		== Example ==

	In case the bases have the same orientation, i.e., <math>\sigma_1=\hat x</math>, <math>\sigma_2 =\hat y</math>, <math>\sigma_3 = \hat z</math> (default)		* In case the bases have the same orientation, i.e., <math>\sigma_1=\hat x</math>, <math>\sigma_2 =\hat y</math>, <math>\sigma_3 = \hat z</math> (default)

	:<math>		:<math>
	\begin{align}		\begin{align}
	m_x & = & m_1 \\		m_x & = & m_1, \\
	m_y & = & m_2 \\		m_y & = & m_2, \\
	m_z & = & m_3		m_z & = & m_3.
	\end{align}		\end{align}
	</math>		</math>
	For a single site this implies setting		:For a single site this implies setting

	{{TAG\|MAGMOM}} = m<sub>x</sub> m<sub>y</sub> m<sub>z</sub> ! magnetic moment in Cartesian coordinates		{{TAG\|MAGMOM}} = m<sub>x</sub> m<sub>y</sub> m<sub>z</sub> ! magnetic moment in Cartesian coordinates
	{{TAG\|SAXIS}} = 0 0 1 ! default		{{TAG\|SAXIS}} = 0 0 1 ! default

	Another good choice is setting <math>\mathbf{s}</math> to point along the direction of the on-site magnetic moment such that		[[File:Spinor-space-example-saxis.png\|300px\|thumb\|Fig 2. Example with <math>\mathbf{s}=(1,1,0)^T</math> and Euler angles <math>\alpha=\pi/4</math> and <math>\beta=\pi/2</math>.]]

			* Another good choice is setting <math>\mathbf{s}</math> to point along the direction of the on-site magnetic moment such that

	:<math>		:<math>
	\begin{align}		\begin{align}
	m_x & = & \sin(\beta)*\cos(\alpha) m &= m s_x / \sqrt{s_x^2+s_y^2+s_z^2} \\		m_x & = & \sin(\beta)\cos(\alpha) m &= m\, s_x / \sqrt{s_x^2+s_y^2+s_z^2} \\
	m_y & = & \sin(\beta)*\sin(\alpha) m &= m s_y / \sqrt{s_x^2+s_y^2+s_z^2} \\		m_y & = & \sin(\beta)\sin(\alpha) m &= m\, s_y / \sqrt{s_x^2+s_y^2+s_z^2} \\
	m_z & = & \cos(\beta) m &= m s_z / \sqrt{s_x^2+s_y^2+s_z^2},		m_z & = & \cos(\beta) m &= m\, s_z / \sqrt{s_x^2+s_y^2+s_z^2},
	\end{align}		\end{align}
	</math>		</math>
	where <math>m</math> is the total on-site magnetic moment.		:where <math>m</math> is the total on-site magnetic moment.
	For a single site, this case implies setting		:For a single site, this case implies setting

	{{TAG\|MAGMOM}} = 0 0 m ! magnetic moment along sigma3		{{TAG\|MAGMOM}} = 0 0 m ! magnetic moment along sigma3
	{{TAG\|SAXIS}} = s<sub>x</sub> s<sub>y</sub> s<sub>z</sub> ! direction of sigma3		{{TAG\|SAXIS}} = s<sub>x</sub> s<sub>y</sub> s<sub>z</sub> ! direction of sigma3
			:Thus, there are two methods to rotate the initial magnetization in an arbitrary direction: either by changing the initial magnetic moments {{TAG\|MAGMOM}} or by changing {{TAG\|SAXIS}}. Both methods should, in principle, yield exactly the same energy, but for implementation reasons, the second method might be more precise.

			* In case

	~~Thus, there are two ways to rotate the spin magnetization in an arbitrary direction: either by changing the initial magnetic moments~~ {{TAG\|~~MAGMOM~~}} ~~or by changing~~ {{~~TAG\|SAXIS~~}}.		{{TAG\|SAXIS}} = 1 1 0 ! alpha=pi/4, beta=pi/2
	~~Both methods should~~, in ~~principle, yield exactly the same energy, but for implementation reasons, the second method might be more precise~~.		:the spinor space <math>\{\sigma_1</math>, <math>\sigma_2</math>, <math>\mathbf{\sigma}_3\}</math> will be rotated with respect to real space <math>\{\hat x, \hat y, \hat z\} </math> as shown in Fig. 2.

	<!---		<!---

Huebsch at 09:15, 21 September 2023

2023-09-21T09:15:18Z

Show changes

Vaspmaster at 17:34, 11 September 2023

2023-09-11T17:34:34Z

← Older revision		Revision as of 17:34, 11 September 2023
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	Where ''m''<sup>axis</sup> is the externally visible magnetic moment. Here, <math>\alpha</math> is the angle between the {{TAG\|SAXIS}} ~~vector~~ (s<sub>x</sub>,s<sub>y</sub>,~~s<sub>z</sub>~~) and the Cartesian vector <math>\hat x</math>, and <math>\beta</math> is the angle between the vector {{TAG\|SAXIS}} and the Cartesian vector <math>\hat z</math>:		Where ''m''<sup>axis</sup> is the externally visible magnetic moment. Here, <math>\alpha</math> is the angle between the projection of {{TAG\|SAXIS}} onto the ''xy''-plane (s<sub>x</sub>,s<sub>y</sub>,0) and the Cartesian vector <math>\hat x</math>, and <math>\beta</math> is the angle between the vector {{TAG\|SAXIS}} and the Cartesian vector <math>\hat z</math>:

	:<math>		:<math>

Karsai: /* Related Tags and Sections */

2022-04-08T14:54:31Z

Related Tags and Sections

← Older revision		Revision as of 14:54, 8 April 2022
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	VASP reads in the {{FILE\|WAVECAR}} and {{FILE\|CHGCAR}} files, aligns the spin quantization axis parallel to {{TAG\|SAXIS}}, which implies that the magnetic field is now parallel to {{TAG\|SAXIS}}, and performs a non selfconsistent calculation. By comparing the energies for different orientations the magnetic anisotropy can be determined. Please mind, that a completely selfconsistent calculation ({{TAG\|ICHARG}} = 1) is in principle also possible with VASP, but this would allow the spinor wavefunctions to rotate from their initial orientation parallel to {{TAG\|SAXIS}} until the correct groundstate is obtained, i.e. until the magnetic moment is parallel to the easy axis. In practice this rotation will be slow, however, since reorientation of the spin gains little energy. Therefore if the convergence criterion is not too tight, sensible results might be obtained even for fully selfconsistent calculations (in the few cases we have tried this worked beautifully).		VASP reads in the {{FILE\|WAVECAR}} and {{FILE\|CHGCAR}} files, aligns the spin quantization axis parallel to {{TAG\|SAXIS}}, which implies that the magnetic field is now parallel to {{TAG\|SAXIS}}, and performs a non selfconsistent calculation. By comparing the energies for different orientations the magnetic anisotropy can be determined. Please mind, that a completely selfconsistent calculation ({{TAG\|ICHARG}} = 1) is in principle also possible with VASP, but this would allow the spinor wavefunctions to rotate from their initial orientation parallel to {{TAG\|SAXIS}} until the correct groundstate is obtained, i.e. until the magnetic moment is parallel to the easy axis. In practice this rotation will be slow, however, since reorientation of the spin gains little energy. Therefore if the convergence criterion is not too tight, sensible results might be obtained even for fully selfconsistent calculations (in the few cases we have tried this worked beautifully).

	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|LNONCOLLINEAR}},		{{TAG\|LNONCOLLINEAR}},
	{{TAG\|MAGMOM}},		{{TAG\|MAGMOM}},
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	----		----

	[[Category:INCAR]][[Category:Magnetism]][[Category:Noncollinear magnetism]]		[[Category:INCAR tag]][[Category:Magnetism]][[Category:Noncollinear magnetism]]

Miranda.henrique at 17:50, 18 November 2020

2020-11-18T17:50:43Z

← Older revision		Revision as of 17:50, 18 November 2020
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	where the default for {{TAG\|SAXIS}} = (0+,0,1) (the notation 0+ implies an infinitesimal small positive number in ''x''-direction). All magnetic moments are now given with respect to the axis		where the default for {{TAG\|SAXIS}} = (0+,0,1) (the notation 0+ implies an infinitesimal small positive number in ''x''-direction). All magnetic moments are now given with respect to the axis
	(s<sub>x</sub>,s<sub>y</sub>,s<sub>z</sub>), where we have adopted the convention '''that all magnetic moments and spinor-like quantities written or read by VASP are given with respect to this axis'''. This includes the {{TAG\|MAGMOM}} line in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file. With respect to the Cartesian ~~lattice vectors~~ the components of the magnetization are (internally) given by		(s<sub>x</sub>,s<sub>y</sub>,s<sub>z</sub>), where we have adopted the convention '''that all magnetic moments and spinor-like quantities written or read by VASP are given with respect to this axis'''. This includes the {{TAG\|MAGMOM}} line in the {{FILE\|INCAR}} file, the total and local magnetizations in the {{FILE\|OUTCAR}} and {{FILE\|PROCAR}} file, the spinor-like orbitals in the {{TAG\|WAVECAR}} file, and the magnetization density in the {{FILE\|CHGCAR}} file. With respect to the Cartesian coordinates, the components of the magnetization are (internally) given by

	:<math>		:<math>