CH LSPEC - Revision history

Karsai at 15:51, 20 February 2025

2025-02-20T15:51:35Z

← Older revision		Revision as of 15:51, 20 February 2025
Line 14:		Line 14:

	And following tags to control the calculation of the dieletric function:		And following tags to control the calculation of the dieletric function:
	*{{TAG\|CH_LSPEC}}: To obtain X-ray absorption spectra (XAS) the following flag has to be set {{TAG\|CH_LSPEC}}=''.TRUE.''.
	{{TAG\|CH_SIGMA}}: The broadening of the spectrum is by default of Gaussian form and the broadening width in eV is set by {{TAG\|CH_SIGMA}}. We recommend using a very small broadening {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and to broaden the spectrum in post-processing. Also, the spectrum can be recalculated with different parameters without the need to redo the electronic self-consistent field cycle. For that one can use the converged {{TAG\|WAVECAR}} from the previous calculation and set {{TAG\|ALGO}}=''None'' together with the new parameters for the spectrum "CH_" in the {{TAG\|INCAR}} file.		{{TAG\|CH_SIGMA}}: The broadening of the spectrum is by default of Gaussian form and the broadening width in eV is set by {{TAG\|CH_SIGMA}}. We recommend using a very small broadening {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and to broaden the spectrum in post-processing. Also, the spectrum can be recalculated with different parameters without the need to redo the electronic self-consistent field cycle. For that one can use the converged {{TAG\|WAVECAR}} from the previous calculation and set {{TAG\|ALGO}}=''None'' together with the new parameters for the spectrum "CH_" in the {{TAG\|INCAR}} file.
	*{{TAG\|CH_NEDOS}}: Sets the number of grid points on the energy axis of the spectrum.		*{{TAG\|CH_NEDOS}}: Sets the number of grid points on the energy axis of the spectrum.

Karsai at 15:51, 20 February 2025

2025-02-20T15:51:12Z

← Older revision		Revision as of 15:51, 20 February 2025
Line 4:		Line 4:
	Description: This flag controls whether the dielecectric function using the supercell core-hole method is calculated or not.		Description: This flag controls whether the dielecectric function using the supercell core-hole method is calculated or not.
	----		----
	How to calculate ~~XAS~~ spectra from core-hole ~~calculations~~ is explained ~~here:~~ [[~~SCH~~ calculations\|~~SCH calculations~~]].		How to calculate X-ray absorption spectra from the supercell core-hole method are is explained [[Supercell core-hole calculations\|here]].

	This ~~feature is~~ only ~~available from VASP version 6~~.0 ~~or higher~~.		This tag should be used in combination with the following important tags for the core-hole approximation:
			*{{TAG\|ICORELEVEL}}: To enable core-hole calculations in the final-state approximation with self-consistent field cycles (SCF) one has to set {{TAG\|ICORELEVEL}}=2. Core-hole calculations in the initial-state approximation ({{TAG\|ICORELEVEL}}=1) are also available, but they are physically less relevant and should be only used if especially needed.
			*{{TAG\|CLNT}}: This tag selects the species holding the core hole. This number corresponds to the species defined in the {{TAG\|POSCAR}} and {{TAG\|POTCAR}} files.
			*{{TAG\|CLN}}: Specifies the <math>n</math> quantum number of the excited electron.
			*{{TAG\|CLL}}: Specifies the <math>l</math> quantum number of the excited electron.
			*{{TAG\|CLZ}}: Specifies how much of a faction of the chosen electron should be excited. Usually one always sets {{TAG\|CLZ}}=1.0, but in some cases values lesser than 1 can lead to better agreement with experiment. However, this should be handled with caution since the physics behind is very dubious.

	~~The broadening type~~ of the ~~spectrum is controlled by~~ {{TAG\|~~ISMEAR~~}} and the broadening in eV is set by {{TAG\|CH_SIGMA}}. We recommend ~~to use~~ a very small ~~Gaussian~~ broadening ~~{{TAG\|ISMEAR}}=0 and~~ {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and broaden the spectrum in post processing. ~~If another type of {{TAG\|ISMEAR}} is required for~~ the electronic ~~calculation,~~ one can ~~run that in a first step and~~ use the converged {{TAG\|WAVECAR}} from ~~that step together with~~ {{TAG\|ALGO}}=''None'' ~~and~~ {{TAG\|~~ISMEAR~~}}~~=0 in~~ a ~~second step~~ to ~~obtain~~ the spectrum.		And following tags to control the calculation of the dieletric function:
			*{{TAG\|CH_LSPEC}}: To obtain X-ray absorption spectra (XAS) the following flag has to be set {{TAG\|CH_LSPEC}}=''.TRUE.''.
			{{TAG\|CH_SIGMA}}: The broadening of the spectrum is by default of Gaussian form and the broadening width in eV is set by {{TAG\|CH_SIGMA}}. We recommend using a very small broadening {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and to broaden the spectrum in post-processing. Also, the spectrum can be recalculated with different parameters without the need to redo the electronic self-consistent field cycle. For that one can use the converged {{TAG\|WAVECAR}} from the previous calculation and set {{TAG\|ALGO}}=''None'' together with the new parameters for the spectrum "CH_" in the {{TAG\|INCAR}} file.
			*{{TAG\|CH_NEDOS}}: Sets the number of grid points on the energy axis of the spectrum.
			*{{TAG\|CH_AMPLIFICATION}}: Scaling of the spectrum by the specified value. This tag is not important but can be useful sometimes if one needs to scale the spectrum a priori. Otherwise, it is recommended to scale the spectrum a posteriori.

	{{NB\|warning\|For XAS calculations it is strongly recommended to use the available GW PAW potentials for the {{TAG\|POTCAR}} files, since many standard potentials don't have projectors with quantum numbers 2 or larger and the GW potentials are more exact for excited states than the standard potentials.}}		{{NB\|warning\|For XAS calculations it is strongly recommended to use the available GW PAW potentials for the {{TAG\|POTCAR}} files, since many standard potentials don't have projectors with quantum numbers 2 or larger and the GW potentials are more exact for excited states than the standard potentials.}}

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}, {{TAG\|CH_AMPLIFICATION}}		{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|CH_AMPLIFICATION}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}, {{TAG\|CH_AMPLIFICATION}}

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

Karsai at 15:45, 20 February 2025

2025-02-20T15:45:58Z

← Older revision		Revision as of 15:45, 20 February 2025
Line 2:		Line 2:
	{{TAGDEF\|CH_LSPEC\|[logical]\|.FALSE.}}		{{TAGDEF\|CH_LSPEC\|[logical]\|.FALSE.}}

	Description: This flag controls whether the ~~imaginary part of~~ the ~~dielectric function for a selected~~ core ~~electron~~ is calculated ~~and written to the {{TAG\|OUTCAR}} file~~ or not.		Description: This flag controls whether the dielecectric function using the supercell core-hole method is calculated or not.
	----		----
	How to calculate XAS spectra from core-hole calculations is explained here: [[SCH calculations\|SCH calculations]].		How to calculate XAS spectra from core-hole calculations is explained here: [[SCH calculations\|SCH calculations]].

Karsai: /* Related tags and articles */

2025-01-28T11:38:49Z

Huebsch at 14:36, 20 February 2024

2024-02-20T14:36:56Z

← Older revision		Revision as of 14:36, 20 February 2024
Line 18:		Line 18:
	----		----

	[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]][[Category:XAS~~]][[Category:VASP6~~]]		[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]][[Category:XAS]]

Karsai at 07:54, 19 July 2022

2022-07-19T07:54:25Z

← Older revision		Revision as of 07:54, 19 July 2022
Line 18:		Line 18:
	----		----

	[[Category:INCAR tag]][[Category:Dielectric ~~Properties~~]][[Category:XAS]][[Category:VASP6]]		[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]][[Category:XAS]][[Category:VASP6]]

Karsai at 06:50, 19 July 2022

2022-07-19T06:50:33Z

← Older revision		Revision as of 06:50, 19 July 2022
Line 4:		Line 4:
	Description: This flag controls whether the imaginary part of the dielectric function for a selected core electron is calculated and written to the {{TAG\|OUTCAR}} file or not.		Description: This flag controls whether the imaginary part of the dielectric function for a selected core electron is calculated and written to the {{TAG\|OUTCAR}} file or not.
	----		----
	How to XAS spectra from core-hole calculations is explained here: [[SCH calculations\|SCH calculations]].		How to calculate XAS spectra from core-hole calculations is explained here: [[SCH calculations\|SCH calculations]].

	This feature is only available from VASP version 6.0 or higher.		This feature is only available from VASP version 6.0 or higher.

Karsai: /* Related tags and articles */

2022-07-19T06:50:04Z

Karsai at 15:27, 7 April 2022

2022-04-07T15:27:41Z

← Older revision		Revision as of 15:27, 7 April 2022
Line 1:		Line 1:
	{{DISPLAYTITLE:CH_LSPEC}}		{{DISPLAYTITLE:CH_LSPEC}}

	{{TAGDEF\|CH_LSPEC\|[logical]\|.FALSE.}}		{{TAGDEF\|CH_LSPEC\|[logical]\|.FALSE.}}

Karsai at 06:46, 7 April 2022

2022-04-07T06:46:26Z

← Older revision		Revision as of 06:46, 7 April 2022
Line 19:		Line 19:
	----		----

	[[Category:INCAR ~~tags~~]][[Category:Dielectric Properties]][[Category:XAS]][[Category:VASP6]]		[[Category:INCAR tag]][[Category:Dielectric Properties]][[Category:XAS]][[Category:VASP6]]

← Older revision		Revision as of 15:51, 20 February 2025
Line 4:		Line 4:
	Description: This flag controls whether the dielecectric function using the supercell core-hole method is calculated or not.		Description: This flag controls whether the dielecectric function using the supercell core-hole method is calculated or not.
	----		----
	How to calculate ~~XAS~~ spectra from core-hole ~~calculations~~ is explained ~~here:~~ [[~~SCH~~ calculations\|~~SCH calculations~~]].		How to calculate X-ray absorption spectra from the supercell core-hole method are is explained [[Supercell core-hole calculations\|here]].

	This ~~feature is~~ only ~~available from VASP version 6~~.0 ~~or higher~~.		This tag should be used in combination with the following important tags for the core-hole approximation:
			*{{TAG\|ICORELEVEL}}: To enable core-hole calculations in the final-state approximation with self-consistent field cycles (SCF) one has to set {{TAG\|ICORELEVEL}}=2. Core-hole calculations in the initial-state approximation ({{TAG\|ICORELEVEL}}=1) are also available, but they are physically less relevant and should be only used if especially needed.
			*{{TAG\|CLNT}}: This tag selects the species holding the core hole. This number corresponds to the species defined in the {{TAG\|POSCAR}} and {{TAG\|POTCAR}} files.
			*{{TAG\|CLN}}: Specifies the <math>n</math> quantum number of the excited electron.
			*{{TAG\|CLL}}: Specifies the <math>l</math> quantum number of the excited electron.
			*{{TAG\|CLZ}}: Specifies how much of a faction of the chosen electron should be excited. Usually one always sets {{TAG\|CLZ}}=1.0, but in some cases values lesser than 1 can lead to better agreement with experiment. However, this should be handled with caution since the physics behind is very dubious.

	~~The broadening type~~ of the ~~spectrum is controlled by~~ {{TAG\|~~ISMEAR~~}} and the broadening in eV is set by {{TAG\|CH_SIGMA}}. We recommend ~~to use~~ a very small ~~Gaussian~~ broadening ~~{{TAG\|ISMEAR}}=0 and~~ {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and broaden the spectrum in post processing. ~~If another type of {{TAG\|ISMEAR}} is required for~~ the electronic ~~calculation,~~ one can ~~run that in a first step and~~ use the converged {{TAG\|WAVECAR}} from ~~that step together with~~ {{TAG\|ALGO}}=''None'' ~~and~~ {{TAG\|~~ISMEAR~~}}~~=0 in~~ a ~~second step~~ to ~~obtain~~ the spectrum.		And following tags to control the calculation of the dieletric function:
			*{{TAG\|CH_LSPEC}}: To obtain X-ray absorption spectra (XAS) the following flag has to be set {{TAG\|CH_LSPEC}}=''.TRUE.''.
			{{TAG\|CH_SIGMA}}: The broadening of the spectrum is by default of Gaussian form and the broadening width in eV is set by {{TAG\|CH_SIGMA}}. We recommend using a very small broadening {{TAG\|CH_SIGMA}}<math>\le</math>0.001 in the calculations and to broaden the spectrum in post-processing. Also, the spectrum can be recalculated with different parameters without the need to redo the electronic self-consistent field cycle. For that one can use the converged {{TAG\|WAVECAR}} from the previous calculation and set {{TAG\|ALGO}}=''None'' together with the new parameters for the spectrum "CH_" in the {{TAG\|INCAR}} file.
			*{{TAG\|CH_NEDOS}}: Sets the number of grid points on the energy axis of the spectrum.
			*{{TAG\|CH_AMPLIFICATION}}: Scaling of the spectrum by the specified value. This tag is not important but can be useful sometimes if one needs to scale the spectrum a priori. Otherwise, it is recommended to scale the spectrum a posteriori.

	{{NB\|warning\|For XAS calculations it is strongly recommended to use the available GW PAW potentials for the {{TAG\|POTCAR}} files, since many standard potentials don't have projectors with quantum numbers 2 or larger and the GW potentials are more exact for excited states than the standard potentials.}}		{{NB\|warning\|For XAS calculations it is strongly recommended to use the available GW PAW potentials for the {{TAG\|POTCAR}} files, since many standard potentials don't have projectors with quantum numbers 2 or larger and the GW potentials are more exact for excited states than the standard potentials.}}

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}, {{TAG\|CH_AMPLIFICATION}}		{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|CH_AMPLIFICATION}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}, {{TAG\|CH_AMPLIFICATION}}

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

← Older revision		Revision as of 11:38, 28 January 2025
Line 13:		Line 13:

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}		{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}, {{TAG\|CH_AMPLIFICATION}}

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

← Older revision		Revision as of 06:50, 19 July 2022
Line 13:		Line 13:

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|CH_SIGMA}},{{TAG\|CH_NEDOS}},{{TAG\|ICORELEVEL}},{{TAG\|CLNT}},{{TAG\|CLN}},{{TAG\|CLL}},{{TAG\|CLZ}},{{TAG\|ISMEAR}}		{{TAG\|CH_SIGMA}}, {{TAG\|CH_NEDOS}}, {{TAG\|ICORELEVEL}}, {{TAG\|CLNT}}, {{TAG\|CLN}}, {{TAG\|CLL}}, {{TAG\|CLZ}}, {{TAG\|ISMEAR}}

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