LMAXFOCKAE - Revision history

Huebsch: Replaced content with "#REDIRECT NMAXFOCKAE and LMAXFOCKAE"

2025-02-28T10:20:44Z

Replaced content with "#REDIRECT NMAXFOCKAE and LMAXFOCKAE"

← Older revision		Revision as of 10:20, 28 February 2025
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	#REDIRECT [[NMAXFOCKAE and LMAXFOCKAE]]		#REDIRECT [[NMAXFOCKAE and LMAXFOCKAE]]

	~~{{TAGDEF\|LMAXFOCKAE\|[integer]}}~~
	~~{{DEF\|LMAXFOCKAE\|-1\|for Hartree-Fock and hybrid functionals \| 4 \| for post DFT methods}}~~

	~~Description: {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} determine whether~~
	the overlap densities in the Fock exchange and correlated wave function methods are accurately reconstructed on the plane wave grid. This flag generally only applies to the Fock-exchange part as well as many-body
	~~post DFT methods (GW, RPA, MP2, etc.).~~

	~~----~~
	~~In the PAW method, the difference between the charge density of the all-electron partial waves <math>\phi_\beta</math> and~~
	~~the pseudo partial waves <math>\tilde \phi_\beta</math>~~
	~~<math>~~
	~~Q_{\alpha\beta}(r)= \phi^_\alpha(r)\phi_\beta(r) - \tilde \phi^_\alpha(r)\tilde \phi_\beta(r)~~
	~~</math>~~
	~~is usually restored on spherical grids centered at each atom~~
	~~(one-center terms inside the PAW spheres). To describe long range electrostatic effect, the ''moments'' of the differences of the all-electron and pseudo charge density~~
	~~also need to added to the pseudo density on the plane wave grid. This is done up to a certain ''l'' quantum number.~~
	~~These augmentation charges exactly restore the moments of the all-electron density on the plane wave~~
	~~grid. For the charge densities used in the Hartree and DFT term,~~
	~~this augmentation is done exactly up to the maximum ''l'' quantum number required by the POTCAR files,~~
	~~whereas for the Fock exchange, the augmentation on the plane wave grid is controlled by {{TAG\|LMAXFOCK}}.~~

	~~For the RPA, GW, and most post DFT methods, the one-center terms are, however, presently~~
	~~not implemented. Depending on the material, this can cause sizable errors~~
	~~in particular for 3d and (to a lesser extent) 2p, 4d and 5d elements.~~
	~~To correct for this error, an alternative treatment is implemented~~
	~~on the plane wave grid. This allows to restore the all-electron densities accurately on the plane wave grid~~
	~~instead of the one-center grids by specifying the flags {{TAG\|LMAXFOCKAE}} and {{TAG\|NMAXFOCKAE}}.~~

	~~To achieve this improved treatment on the plane wave grid, <math> Q_{\alpha\beta}(r) </math> is Fourier transformed to reciprocal space <math> Q_{\alpha\beta}(q) </math> and then expanded~~
	~~in a set of orthogonal functions localized at each atomic site. These augmentation charges~~
	~~are then added to the pseudo charge densities on the plane wave grid.~~


	For {{TAG\|LMAXFOCKAE}}=-1 (the default for DFT and Hartree-Fock calculations), only the moments of the all-electron charge densities are restored on the plane wave grid. This setting is exact for Hartree-Fock
	~~since the one-center terms are implemented.~~

	If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up
	~~to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4 for post DFT methods.~~
	~~If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.~~

	If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 and {{TAG\|NMAXFOCKAE}}=2, the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 380 eV. As before, {{TAG\|LMAXFOCKAE}} can be used to specify the maximum spherical (l) quantum number up
	~~to which this more accurate treatment is used. {{TAG\|NMAXFOCKAE}}=2 yields very accurate results for~~
	post DFT methods (MP2, RPA, GW) even for difficult 3d elements. For RPA and MP2 total energy calculations, differences between {{TAG\|NMAXFOCKAE}}=1 and {{TAG\|NMAXFOCKAE}}=2 are usually tiny for total energy differences. Since the absolute correlation energies might change, it is vital to use the same setting for
	~~{{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}}, if energy differences are calculated.~~
	~~For GW calculations, increasing {{TAG\|NMAXFOCKAE}} from 1 to 2 might change QP energies by 100-200 meV for 3d and late 4d and 5d elements.~~


	~~The setting for {{TAG\|LMAXFOCKAE}} should be also considered carefully. Generally, it suffices to set {{TAG\|LMAXFOCKAE}} to twice the maximum ''l'' quantum number found in the {{FILE\|POTCAR}} file.~~
	~~For instance for sp elements, {{TAG\|LMAXFOCKAE}} = 2 suffices. For d elements, {{TAG\|LMAXFOCKAE}} = 4 suffices~~
	~~(a d electron can create charge densities with ''l''-quantum numbers up to 4), whereas for f elements, users~~
	~~should test whether {{TAG\|LMAXFOCKAE}} = 6 is required.~~

	~~In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:~~
	* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether
	* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the charge augmentation on the plane wave grid (can be selected even in Hartree-Fock type calculations).
	* {{TAG\|NMAXFOCKAE}}=2, to select the very accurate augmentation on the plane wave grid. Please check whether the VASP default setting for {{TAG\|LMAXFOCKAE}} suffices (OUTCAR file).


	~~== Related tags and articles ==~~
	~~{{TAG\|LMAXFOCK}}, {{TAG\|NMAXFOCKAE}}, {{TAG\|QMAXFOCKAE}}, {{TAG\|LFOCKAEDFT}}~~
	~~----~~

	~~[[Category:INCAR tag]][[Category:Hybrids]][[Category:GW]]~~

Karsai: /* Related Tags and Sections */

2022-04-08T14:38:52Z

Related Tags and Sections

← Older revision		Revision as of 14:38, 8 April 2022
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	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|LMAXFOCK}}, {{TAG\|NMAXFOCKAE}}, {{TAG\|QMAXFOCKAE}}, {{TAG\|LFOCKAEDFT}}		{{TAG\|LMAXFOCK}}, {{TAG\|NMAXFOCKAE}}, {{TAG\|QMAXFOCKAE}}, {{TAG\|LFOCKAEDFT}}
	----		----
	~~[[The_VASP_Manual\|Contents]]~~

	[[Category:INCAR]][[Category:Hybrids]][[Category:GW]]		[[Category:INCAR tag]][[Category:Hybrids]][[Category:GW]]

Vaspmaster: Redirected page to NMAXFOCKAE and LMAXFOCKAE

2017-03-15T12:06:12Z

Redirected page to NMAXFOCKAE and LMAXFOCKAE

← Older revision		Revision as of 12:06, 15 March 2017
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			#REDIRECT [[NMAXFOCKAE and LMAXFOCKAE]]

	{{TAGDEF\|LMAXFOCKAE\|[integer]}}		{{TAGDEF\|LMAXFOCKAE\|[integer]}}
	{{DEF\|LMAXFOCKAE\|-1\|for Hartree-Fock and hybrid functionals \| 4 \| for post DFT methods}}		{{DEF\|LMAXFOCKAE\|-1\|for Hartree-Fock and hybrid functionals \| 4 \| for post DFT methods}}

Kresse at 16:22, 14 March 2017

2017-03-14T16:22:11Z

← Older revision		Revision as of 16:22, 14 March 2017
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	----		----
	In the PAW method, the difference between the charge density of the all-electron partial waves and		In the PAW method, the difference between the charge density of the all-electron partial waves <math>\phi_\beta</math> and
	the pseudo partial waves		the pseudo partial waves <math>\tilde \phi_\beta</math>
	<math>		<math>
	Q_{\alpha\beta}(r)= \phi^_\alpha(r)\phi_\beta(r) - \tilde \phi^_\alpha(r)\tilde \phi_\beta(r)		Q_{\alpha\beta}(r)= \phi^_\alpha(r)\phi_\beta(r) - \tilde \phi^_\alpha(r)\tilde \phi_\beta(r)
	</math>		</math>
	is usually restored on spherical grids centered at each atom		is usually restored on spherical grids centered at each atom
	(one-center terms inside the PAW spheres). To describe long range electrostatic ~~terms~~, the ''moments'' of the differences of the all-electron and pseudo charge density ~~are usually~~		(one-center terms inside the PAW spheres). To describe long range electrostatic effect, the ''moments'' of the differences of the all-electron and pseudo charge density
	also added on the plane wave grid up to a certain ''l'' quantum number ~~(see {{TAG\|LMAXFOCK}})~~.		also need to added to the pseudo density on the plane wave grid. This is done up to a certain ''l'' quantum number.
	These augmentation charges restore the moments of the all-electron density on the plane wave		These augmentation charges exactly restore the moments of the all-electron density on the plane wave
	grid.		grid. For the charge densities used in the Hartree and DFT term,
			this augmentation is done exactly up to the maximum ''l'' quantum number required by the POTCAR files,
			whereas for the Fock exchange, the augmentation on the plane wave grid is controlled by {{TAG\|LMAXFOCK}}.

	For the RPA, GW, and most post DFT methods, the one-center terms are ~~presently~~,		For the RPA, GW, and most post DFT methods, the one-center terms are, however, presently
	however, not implemented. Depending on the material, this can cause sizable errors		not implemented. Depending on the material, this can cause sizable errors
	in particular for 3d and (to a lesser extent) 2p, 4d and 5d elements.		in particular for 3d and (to a lesser extent) 2p, 4d and 5d elements.
	To correct for this error, an alternative treatment is implemented		To correct for this error, an alternative treatment is implemented

Kresse: /* Related Tags and Sections */

2017-03-14T15:27:45Z

Related Tags and Sections

← Older revision		Revision as of 15:27, 14 March 2017
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	== Related Tags and Sections ==		== Related Tags and Sections ==
	{{TAG\|LMAXFOCK}}, {{TAG\|NMAXFOCKAE}}, {{TAG\|QMAXFOCKAE}}		{{TAG\|LMAXFOCK}}, {{TAG\|NMAXFOCKAE}}, {{TAG\|QMAXFOCKAE}}, {{TAG\|LFOCKAEDFT}}
	----		----
	[[The_VASP_Manual\|Contents]]		[[The_VASP_Manual\|Contents]]

	[[Category:INCAR]][[Category:Hybrids]][[Category:GW]]		[[Category:INCAR]][[Category:Hybrids]][[Category:GW]]

Kresse at 15:25, 14 March 2017

2017-03-14T15:25:01Z

← Older revision		Revision as of 15:25, 14 March 2017
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	In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:		In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:
	* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether		* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether
	* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the ~~HF part~~ even in Hartree-Fock calculations		* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the charge augmentation on the plane wave grid (can be selected even in Hartree-Fock type calculations).
	* {{TAG\|NMAXFOCKAE}}=2, to select the very accurate augmentation. Please check whether the VASP default setting for {{TAG\|LMAXFOCKAE}} suffices (OUTCAR file).		* {{TAG\|NMAXFOCKAE}}=2, to select the very accurate augmentation on the plane wave grid. Please check whether the VASP default setting for {{TAG\|LMAXFOCKAE}} suffices (OUTCAR file).

Kresse at 15:23, 14 March 2017

2017-03-14T15:23:52Z

← Older revision		Revision as of 15:23, 14 March 2017
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	should test whether {{TAG\|LMAXFOCKAE}} = 6 is required.		should test whether {{TAG\|LMAXFOCKAE}} = 6 is required.

	In summary, ~~usefully~~ manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:		In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:
	* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether		* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether
	* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the HF part even in Hartree-Fock calculations		* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the HF part even in Hartree-Fock calculations

Kresse at 15:22, 14 March 2017

2017-03-14T15:22:25Z

← Older revision		Revision as of 15:22, 14 March 2017
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	If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.		If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.

	If {{TAG\|LMAXFOCKAE}} is set to ~~value~~ larger than -1 and {{TAG\|NMAXFOCKAE}}=2, the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 380 eV. As before, {{TAG\|LMAXFOCKAE}} can be used to specify the maximum spherical (l) quantum number up		If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 and {{TAG\|NMAXFOCKAE}}=2, the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 380 eV. As before, {{TAG\|LMAXFOCKAE}} can be used to specify the maximum spherical (l) quantum number up
	to which this more accurate treatment is used. {{TAG\|NMAXFOCKAE}}=2 yields very accurate results for		to which this more accurate treatment is used. {{TAG\|NMAXFOCKAE}}=2 yields very accurate results for
	post DFT methods (MP2, RPA, GW) even for difficult 3d elements. For RPA and MP2 total energy calculations, differences between {{TAG\|NMAXFOCKAE}}=1 and {{TAG\|NMAXFOCKAE}}=2 are usually tiny for total energy differences. Since the absolute correlation energies might change, it is vital to use the same setting for		post DFT methods (MP2, RPA, GW) even for difficult 3d elements. For RPA and MP2 total energy calculations, differences between {{TAG\|NMAXFOCKAE}}=1 and {{TAG\|NMAXFOCKAE}}=2 are usually tiny for total energy differences. Since the absolute correlation energies might change, it is vital to use the same setting for

Kresse at 15:21, 14 March 2017

2017-03-14T15:21:56Z

← Older revision		Revision as of 15:21, 14 March 2017
Line 34:		Line 34:

	If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up		If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up
	to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4, for post DFT methods.		to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4 for post DFT methods.
	If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.		If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.

Kresse at 15:21, 14 March 2017

2017-03-14T15:21:04Z

← Older revision		Revision as of 15:21, 14 March 2017
Line 33:		Line 33:
	since the one-center terms are implemented.		since the one-center terms are implemented.

	If {{TAG\|LMAXFOCKAE}} is set to ~~value~~ larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up		If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up
	to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4, for post DFT methods.		to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4, for post DFT methods.
	If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.		If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.

← Older revision		Revision as of 15:25, 14 March 2017
Line 51:		Line 51:
	In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:		In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:
	* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether		* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether
	* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the ~~HF part~~ even in Hartree-Fock calculations		* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the charge augmentation on the plane wave grid (can be selected even in Hartree-Fock type calculations).
	* {{TAG\|NMAXFOCKAE}}=2, to select the very accurate augmentation. Please check whether the VASP default setting for {{TAG\|LMAXFOCKAE}} suffices (OUTCAR file).		* {{TAG\|NMAXFOCKAE}}=2, to select the very accurate augmentation on the plane wave grid. Please check whether the VASP default setting for {{TAG\|LMAXFOCKAE}} suffices (OUTCAR file).

← Older revision		Revision as of 15:23, 14 March 2017
Line 49:		Line 49:
	should test whether {{TAG\|LMAXFOCKAE}} = 6 is required.		should test whether {{TAG\|LMAXFOCKAE}} = 6 is required.

	In summary, ~~usefully~~ manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:		In summary, useful manual settings of {{TAG\|NMAXFOCKAE}} and {{TAG\|LMAXFOCKAE}} are:
	* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether		* {{TAG\|LMAXFOCKAE}}=-1, to switch off the accurate augmentation altogether
	* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the HF part even in Hartree-Fock calculations		* {{TAG\|LMAXFOCKAE}}=4 (or larger) to force an accurate treatment for the HF part even in Hartree-Fock calculations

← Older revision		Revision as of 15:22, 14 March 2017
Line 37:		Line 37:
	If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.		If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.

	If {{TAG\|LMAXFOCKAE}} is set to ~~value~~ larger than -1 and {{TAG\|NMAXFOCKAE}}=2, the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 380 eV. As before, {{TAG\|LMAXFOCKAE}} can be used to specify the maximum spherical (l) quantum number up		If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 and {{TAG\|NMAXFOCKAE}}=2, the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 380 eV. As before, {{TAG\|LMAXFOCKAE}} can be used to specify the maximum spherical (l) quantum number up
	to which this more accurate treatment is used. {{TAG\|NMAXFOCKAE}}=2 yields very accurate results for		to which this more accurate treatment is used. {{TAG\|NMAXFOCKAE}}=2 yields very accurate results for
	post DFT methods (MP2, RPA, GW) even for difficult 3d elements. For RPA and MP2 total energy calculations, differences between {{TAG\|NMAXFOCKAE}}=1 and {{TAG\|NMAXFOCKAE}}=2 are usually tiny for total energy differences. Since the absolute correlation energies might change, it is vital to use the same setting for		post DFT methods (MP2, RPA, GW) even for difficult 3d elements. For RPA and MP2 total energy calculations, differences between {{TAG\|NMAXFOCKAE}}=1 and {{TAG\|NMAXFOCKAE}}=2 are usually tiny for total energy differences. Since the absolute correlation energies might change, it is vital to use the same setting for

← Older revision		Revision as of 15:21, 14 March 2017
Line 34:		Line 34:

	If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up		If {{TAG\|LMAXFOCKAE}} is set to values larger than -1 (and {{TAG\|NMAXFOCKAE}}=1), not only the moments of the all-electron charge density are restored, but also the all-electron charge density is restored up to a typical plane wave energy of 140 eV. This setting yields very accurate results for post DFT methods (MP2, RPA, GW, etc.) for most sp bonded materials. {{TAG\|LMAXFOCKAE}} is used to specify the maximum spherical (l) quantum number up
	to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4, for post DFT methods.		to which this more accurate treatment is used. The default is {{TAG\|LMAXFOCKAE}}=4 for post DFT methods.
	If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.		If no accurate augmentation is desired by the user, simply set {{TAG\|LMAXFOCKAE}}=-1 in the INCAR file.