LDAUTYPE - Revision history

Ftran at 16:22, 27 February 2025

2025-02-27T16:22:13Z

← Older revision		Revision as of 16:22, 27 February 2025
Line 3:		Line 3:
	Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	The following variants of the [[DFT+U~~: formalism~~\|DFT+U ~~approach~~]] are available:		The following variants of the [[:Category:DFT+U\|DFT+U]] are available:

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}

Ftran at 15:49, 27 February 2025

2025-02-27T15:49:23Z

← Older revision		Revision as of 15:49, 27 February 2025
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	{{TAG\|LDAUJ}},		{{TAG\|LDAUJ}},
	{{TAG\|LDAUPRINT}},		{{TAG\|LDAUPRINT}},
	{{TAG\|LMAXMIX~~}},~~		{{TAG\|LMAXMIX}}
	~~{{TAG\|DFT+U: formalism~~}}

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

Huebsch at 08:53, 9 May 2023

2023-05-09T08:53:08Z

← Older revision		Revision as of 08:53, 9 May 2023
Line 3:		Line 3:
	Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	~~Three~~ variants of the ~~DFT+U approach are available in VASP (a brief overview is given~~ [[DFT+U: formalism\|~~here~~]]):		The following variants of the [[DFT+U: formalism\|DFT+U approach]] are available:

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}

	*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to ~~the~~ DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}		*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}

	*{{TAG\|LDAUTYPE}}=4: ~~same as~~ {{TAG\|LDAUTYPE}}=1, ~~but without exchange splitting~~.		*{{TAG\|LDAUTYPE}}=3: Linear response ansatz of Cococcioni et al. {{cite\|cococcioni:2005}} to compute U. See [[Calculate U for LSDA+U\|how to calculate U]].
			{{NB\|mind\|For {{TAG\|LDAUTYPE}}{{=}}3, the {{TAG\|LDAUU}} and {{TAG\|LDAUJ}} tags specify the strength of the spherical potential acting on the spin-up and spin-down manifolds, respectively.\|:}}

	~~----~~		*{{TAG\|LDAUTYPE}}=4: Same as {{TAG\|LDAUTYPE}}=1, but without exchange splitting.
	~~'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> (~~{{TAG\|~~LDAUU~~}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).

	~~'''Note on~~ band structure ~~calculation''':~~ the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number ~~<math>l</math>=~~{{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. ~~For~~ the ~~calculation of band structures within the DFT+~~U ~~approach, it is hence strictly required to increase~~ {{TAG\|~~LMAXMIX~~}} to ~~4 (~~<math>d</math> ~~elements)~~ and ~~6 (~~<math>f</math> ~~elements~~).		A method to estimate the parameters for DFT+U is the [[Constrained-random-phase approximation\|constrained-random-phase approximation]]. Another method is the linear response ansatz with {{TAG\|LDAUTYPE}}=3, mentioned above. On the other hand, in many applications, the DFT+U parameters are used as tuning parameters to fit experimental data.
			{{NB\|tip\|For band-structure calculations, increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) or 6 (<math>f</math> elements).}}
			This is because the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number set by {{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will necessarily not be identical to a self-consistent run. The deviations are often large for DFT+U calculations.
			{{NB\|warning\|The total energy will depend on the parameters <math>U</math> ({{TAG\|LDAUU}}) and <math>J</math> ({{TAG\|LDAUJ}}). It is, therefore, not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>; or <math>U-J</math> in the case of Dudarev's approach ({{TAG\|LDAUTYPE}}{{=}}2).}}

			It is possible to use {{TAG\|LDAUTYPE}}=1, 2, and 3 for a non–spin-polarized calculation with {{TAG\|ISPIN}}=1.

	== Related tags and articles ==		== Related tags and articles ==

Ftran at 14:20, 18 October 2022

2022-10-18T14:20:51Z

← Older revision		Revision as of 14:20, 18 October 2022
Line 8:		Line 8:

	*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to the DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}		*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to the DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}
	~~:This flavour of DFT+U is of the following form:~~

	*{{TAG\|LDAUTYPE}}=4: same as {{TAG\|LDAUTYPE}}=1, but without exchange splitting.		*{{TAG\|LDAUTYPE}}=4: same as {{TAG\|LDAUTYPE}}=1, but without exchange splitting.

Ftran at 13:03, 11 April 2022

2022-04-11T13:03:26Z

← Older revision		Revision as of 13:03, 11 April 2022
Line 3:		Line 3:
	Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	Three variants of the DFT+U approach are available in VASP~~, that are described in more detail~~ [[DFT+U: formalism\|here]] ~~are the following~~:		Three variants of the DFT+U approach are available in VASP (a brief overview is given [[DFT+U: formalism\|here]]):

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}
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	'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> ({{TAG\|LDAUU}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).		'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> ({{TAG\|LDAUU}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).

	'''Note on ~~bandstructure~~ calculation''': the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number <math>l</math>={{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. For the calculation of band structures within the DFT+U approach, it is hence strictly required to increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) and 6 (<math>f</math> elements).		'''Note on band structure calculation''': the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number <math>l</math>={{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. For the calculation of band structures within the DFT+U approach, it is hence strictly required to increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) and 6 (<math>f</math> elements).

	== Related tags and articles ==		== Related tags and articles ==
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	{{TAG\|LDAUJ}},		{{TAG\|LDAUJ}},
	{{TAG\|LDAUPRINT}},		{{TAG\|LDAUPRINT}},
	{{TAG\|LMAXMIX}}		{{TAG\|LMAXMIX}},
			{{TAG\|DFT+U: formalism}}

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

Ftran at 12:57, 11 April 2022

2022-04-11T12:57:11Z

← Older revision		Revision as of 12:57, 11 April 2022
Line 3:		Line 3:
	Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	Three variants of the DFT+U ~~approaches~~ are available in VASP, that are described in more detail [[DFT+U: formalism\|here]] are the following:		Three variants of the DFT+U approach are available in VASP, that are described in more detail [[DFT+U: formalism\|here]] are the following:

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}

Ftran at 12:55, 11 April 2022

2022-04-11T12:55:45Z

← Older revision		Revision as of 12:55, 11 April 2022
Line 1:		Line 1:
	{{TAGDEF\|LDAUTYPE\|1 {{!}} 2 {{!}} 4\|2}}		{{TAGDEF\|LDAUTYPE\|1 {{!}} 2 {{!}} 4\|2}}

	Description: {{TAG\|LDAUTYPE}} specifies ~~which type of~~ DFT+U ~~approach~~ will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	Three ~~types~~ of DFT+U approaches are available in VASP~~. These~~ are the following:		Three variants of the DFT+U approaches are available in VASP, that are described in more detail [[DFT+U: formalism\|here]] are the following:

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}

Ftran at 12:44, 11 April 2022

2022-04-11T12:44:32Z

@@ Line 6: / Line 6: @@
 *{{TAG|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite|liechtenstein:prb:95}}
 *{{TAG|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to the DFT+U, introduced by Dudarev ''et al.''{{cite|dudarev:prb:98}}
 :This flavour of DFT+U is of the following form:
-::<math>
+*{{TAG|LDAUTYPE}}=4: same as {{TAG|LDAUTYPE}}=1, but without exchange splitting.
 ----
 '''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> ({{TAG|LDAUU}} and {{TAG|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG|LDAUTYPE}}=2).

Ftran at 12:39, 11 April 2022

2022-04-11T12:39:24Z

← Older revision		Revision as of 12:39, 11 April 2022
Line 24:		Line 24:
	\delta_{s_1 s_2} \delta_{s_3 s_4}		\delta_{s_1 s_2} \delta_{s_3 s_4}
	</math>		</math>
	:where <math>\|m\rangle</math> are real spherical harmonics of angular momentum <math>~~\ell~~</math>={{TAG\|LDAUL}}.		:where <math>\|m\rangle</math> are real spherical harmonics of angular momentum <math>l</math>={{TAG\|LDAUL}}.

	:The unscreened electron-electron interaction <math>U_{\gamma_{1}\gamma_{3}\gamma_{2}\gamma_{4}}</math> can be written in terms of the Slater integrals <math>F^0</math>, <math>F^2</math>, <math>F^4</math>, and <math>F^6</math> (<math>f</math> electrons). Using values for the Slater integrals calculated from atomic orbitals, however, would lead to a large overestimation of the true electron-electron interaction, since in solids the Coulomb interaction is screened (especially <math>F^0</math>).		:The unscreened electron-electron interaction <math>U_{\gamma_{1}\gamma_{3}\gamma_{2}\gamma_{4}}</math> can be written in terms of the Slater integrals <math>F^0</math>, <math>F^2</math>, <math>F^4</math>, and <math>F^6</math> (<math>f</math> electrons). Using values for the Slater integrals calculated from atomic orbitals, however, would lead to a large overestimation of the true electron-electron interaction, since in solids the Coulomb interaction is screened (especially <math>F^0</math>).
Line 80:		Line 80:
	'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> ({{TAG\|LDAUU}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).		'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> ({{TAG\|LDAUU}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).

	'''Note on bandstructure calculation''': the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number <math>~~\ell~~</math>={{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. For the calculation of band structures within the DFT+U approach, it is hence strictly required to increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) and 6 (<math>f</math> elements).		'''Note on bandstructure calculation''': the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number <math>l</math>={{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. For the calculation of band structures within the DFT+U approach, it is hence strictly required to increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) and 6 (<math>f</math> elements).

	== Related tags and articles ==		== Related tags and articles ==

Karsai: /* References */

2022-04-08T14:29:39Z

References

← Older revision		Revision as of 14:29, 8 April 2022
Line 94:		Line 94:
	== References ==		== References ==
	<references/>		<references/>

	----		----
	~~[[The_VASP_Manual\|Contents]]~~

	[[Category:INCAR]][[Category:Exchange-correlation functionals]][[Category:DFT+U]]		[[Category:INCAR tag]][[Category:Exchange-correlation functionals]][[Category:DFT+U]]

← Older revision		Revision as of 15:49, 27 February 2025
Line 27:		Line 27:
	{{TAG\|LDAUJ}},		{{TAG\|LDAUJ}},
	{{TAG\|LDAUPRINT}},		{{TAG\|LDAUPRINT}},
	{{TAG\|LMAXMIX~~}},~~		{{TAG\|LMAXMIX}}
	~~{{TAG\|DFT+U: formalism~~}}

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

← Older revision		Revision as of 08:53, 9 May 2023
Line 3:		Line 3:
	Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.		Description: {{TAG\|LDAUTYPE}} specifies the DFT+U variant that will be used.
	----		----
	~~Three~~ variants of the ~~DFT+U approach are available in VASP (a brief overview is given~~ [[DFT+U: formalism\|~~here~~]]):		The following variants of the [[DFT+U: formalism\|DFT+U approach]] are available:

	*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}		*{{TAG\|LDAUTYPE}}=1: The rotationally invariant DFT+U introduced by Liechtenstein ''et al.''{{cite\|liechtenstein:prb:95}}

	*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to ~~the~~ DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}		*{{TAG\|LDAUTYPE}}=2: The simplified (rotationally invariant) approach to DFT+U, introduced by Dudarev ''et al.''{{cite\|dudarev:prb:98}}

	*{{TAG\|LDAUTYPE}}=4: ~~same as~~ {{TAG\|LDAUTYPE}}=1, ~~but without exchange splitting~~.		*{{TAG\|LDAUTYPE}}=3: Linear response ansatz of Cococcioni et al. {{cite\|cococcioni:2005}} to compute U. See [[Calculate U for LSDA+U\|how to calculate U]].
			{{NB\|mind\|For {{TAG\|LDAUTYPE}}{{=}}3, the {{TAG\|LDAUU}} and {{TAG\|LDAUJ}} tags specify the strength of the spherical potential acting on the spin-up and spin-down manifolds, respectively.\|:}}

	~~----~~		*{{TAG\|LDAUTYPE}}=4: Same as {{TAG\|LDAUTYPE}}=1, but without exchange splitting.
	~~'''Warning''': it is important to be aware of the fact that when using the DFT+U, in general the total energy will depend on the parameters <math>U</math> and <math>J</math> (~~{{TAG\|~~LDAUU~~}} and {{TAG\|LDAUJ}}, respectively). It is therefore not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>, or <math>U-J</math> and in case of Dudarev's approach ({{TAG\|LDAUTYPE}}=2).

	~~'''Note on~~ band structure ~~calculation''':~~ the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number ~~<math>l</math>=~~{{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will be necessarily not identical to a self-consistent run. The deviations are often large for DFT+U calculations. ~~For~~ the ~~calculation of band structures within the DFT+~~U ~~approach, it is hence strictly required to increase~~ {{TAG\|~~LMAXMIX~~}} to ~~4 (~~<math>d</math> ~~elements)~~ and ~~6 (~~<math>f</math> ~~elements~~).		A method to estimate the parameters for DFT+U is the [[Constrained-random-phase approximation\|constrained-random-phase approximation]]. Another method is the linear response ansatz with {{TAG\|LDAUTYPE}}=3, mentioned above. On the other hand, in many applications, the DFT+U parameters are used as tuning parameters to fit experimental data.
			{{NB\|tip\|For band-structure calculations, increase {{TAG\|LMAXMIX}} to 4 (<math>d</math> elements) or 6 (<math>f</math> elements).}}
			This is because the {{FILE\|CHGCAR}} file contains only information up to angular momentum quantum number set by {{TAG\|LMAXMIX}} for the [[LDAUTYPE#occmat\|on-site PAW occupancy matrices]]. When the {{FILE\|CHGCAR}} file is read and kept fixed in the course of the calculations ({{TAG\|ICHARG}}=11), the results will necessarily not be identical to a self-consistent run. The deviations are often large for DFT+U calculations.
			{{NB\|warning\|The total energy will depend on the parameters <math>U</math> ({{TAG\|LDAUU}}) and <math>J</math> ({{TAG\|LDAUJ}}). It is, therefore, not meaningful to compare the total energies resulting from calculations with different <math>U</math> and/or <math>J</math>; or <math>U-J</math> in the case of Dudarev's approach ({{TAG\|LDAUTYPE}}{{=}}2).}}

			It is possible to use {{TAG\|LDAUTYPE}}=1, 2, and 3 for a non–spin-polarized calculation with {{TAG\|ISPIN}}=1.

	== Related tags and articles ==		== Related tags and articles ==