LOPTICS - Revision history

Hampel at 11:36, 12 August 2025

2025-08-12T11:36:59Z

← Older revision		Revision as of 11:36, 12 August 2025
Line 39:		Line 39:
	also much more expensive than {{TAG\|LOPTICS}}=.TRUE.		also much more expensive than {{TAG\|LOPTICS}}=.TRUE.
	=== Spectral broadening ===		=== Spectral broadening ===
	The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods ~~imultaneously~~ and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.		The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods simultaneously and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.

			Note, that the imaginary part of the dielectric function is also broadened by the Lorentzian as long as {{TAG\|CSHIFT}} is not too small, in which case a warning is printed. This means that first a Gaussian broadening is added directly when the imaginary part of the dielectric function is calculated, and successively afterwards a Loretzian broadening is applied. Mind, that this especially affects the life time, i.e. long tails of the transitions, and can influence the dielectric function significantly and produce artifacts if the cut-off frequency {{TAG\|OMEGAMAX}} is chosen close to a large transition element.
	{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}		{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

Tal at 10:57, 17 October 2024

2024-10-17T10:57:32Z

← Older revision		Revision as of 10:57, 17 October 2024
Line 39:		Line 39:
	also much more expensive than {{TAG\|LOPTICS}}=.TRUE.		also much more expensive than {{TAG\|LOPTICS}}=.TRUE.
	=== Spectral broadening ===		=== Spectral broadening ===
	The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid ~~having simultaneously~~ two different broadening methods and only include the Lorentzian broadening one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}} ~~or vice versa for the Gaussian broadening~~.		The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods imultaneously and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.
	{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}		{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

Tal at 10:48, 17 October 2024

2024-10-17T10:48:34Z

← Older revision		Revision as of 10:48, 17 October 2024
Line 38:		Line 38:
	effects beyond the independent particle approximation, however, they are usually		effects beyond the independent particle approximation, however, they are usually
	also much more expensive than {{TAG\|LOPTICS}}=.TRUE.		also much more expensive than {{TAG\|LOPTICS}}=.TRUE.
			=== Spectral broadening ===
			The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid having simultaneously two different broadening methods and only include the Lorentzian broadening one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}} or vice versa for the Gaussian broadening.
	{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}		{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

Huebsch: /* Related tags and articles */

2024-02-02T15:09:23Z

Huebsch: /* Related tags and articles */

2024-02-01T08:43:10Z

Huebsch at 14:27, 19 July 2022

2022-07-19T14:27:32Z

← Older revision		Revision as of 14:27, 19 July 2022
Line 55:		Line 55:
	----		----

	[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric ~~properties]][[Category:Frequency dependent dielectric~~ properties]]		[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]]

Karsai: /* References */

2022-07-19T07:49:55Z

References

← Older revision		Revision as of 07:49, 19 July 2022
Line 55:		Line 55:
	----		----

	[[Category:INCAR tag]][[Category:Dielectric properties]][[Category:Frequency dependent dielectric properties]]		[[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]][[Category:Frequency dependent dielectric properties]]

Karsai: /* References */

2022-07-19T07:47:17Z

References

← Older revision		Revision as of 07:47, 19 July 2022
Line 55:		Line 55:
	----		----

	[[Category:INCAR tag]][[Category:Dielectric ~~Properties~~]][[Category:Frequency dependent dielectric properties]]		[[Category:INCAR tag]][[Category:Dielectric properties]][[Category:Frequency dependent dielectric properties]]

Karsai: /* References */

2022-04-08T14:37:41Z

References

← Older revision		Revision as of 14:37, 8 April 2022
Line 54:		Line 54:
	</references>		</references>
	----		----
	~~[[The_VASP_Manual\|Contents]]~~

	[[Category:INCAR]][[Category:Dielectric Properties]][[Category:Frequency dependent dielectric properties]]		[[Category:INCAR tag]][[Category:Dielectric Properties]][[Category:Frequency dependent dielectric properties]]

Karsai: /* Related Tags and Sections */

2022-04-08T14:37:31Z

Related Tags and Sections

← Older revision		Revision as of 14:37, 8 April 2022
Line 42:		Line 42:
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|CSHIFT}},		{{TAG\|CSHIFT}},
	{{TAG\|LNABLA}},		{{TAG\|LNABLA}},

← Older revision		Revision as of 11:36, 12 August 2025
Line 39:		Line 39:
	also much more expensive than {{TAG\|LOPTICS}}=.TRUE.		also much more expensive than {{TAG\|LOPTICS}}=.TRUE.
	=== Spectral broadening ===		=== Spectral broadening ===
	The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods ~~imultaneously~~ and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.		The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods simultaneously and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.

			Note, that the imaginary part of the dielectric function is also broadened by the Lorentzian as long as {{TAG\|CSHIFT}} is not too small, in which case a warning is printed. This means that first a Gaussian broadening is added directly when the imaginary part of the dielectric function is calculated, and successively afterwards a Loretzian broadening is applied. Mind, that this especially affects the life time, i.e. long tails of the transitions, and can influence the dielectric function significantly and produce artifacts if the cut-off frequency {{TAG\|OMEGAMAX}} is chosen close to a large transition element.
	{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}		{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

← Older revision		Revision as of 10:57, 17 October 2024
Line 39:		Line 39:
	also much more expensive than {{TAG\|LOPTICS}}=.TRUE.		also much more expensive than {{TAG\|LOPTICS}}=.TRUE.
	=== Spectral broadening ===		=== Spectral broadening ===
	The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid ~~having simultaneously~~ two different broadening methods and only include the Lorentzian broadening one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}} ~~or vice versa for the Gaussian broadening~~.		The dielectric function calculated with {{TAG\|LOPTICS}} includes broadening due to the smearing method {{TAG\|ISMEAR}} and the Lorentzian broadening due to the complex shift in the Kramers-Kronig transformation. For example, the combination of {{TAG\|LOPTICS}}=.TRUE. and {{TAG\|ISMEAR}}=0 produces the dielectric function broadened by a Gaussian with the width {{TAG\|SIGMA}} and a Lorentzian with the width {{TAG\|CSHIFT}}. To avoid using two different broadening methods imultaneously and only include the Lorentzian broadening, one should set {{TAG\|SIGMA}} to a much smaller value than {{TAG\|CSHIFT}}.
	{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}		{{NB\|warning\|Note that {{TAG\|LOPTICS}} {{=}} .TRUE. with {{TAG\|ISMEAR}} {{=}} -2 is currently not supported.}}
	{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}		{{NB\|mind\|Furthermore the combination of {{TAG\|LOPTICS}} {{=}} .TRUE. and {{TAG\|ISMEAR}} selecting the tetrahedron method is only supported as of VASP 6.3.}}

← Older revision		Revision as of 15:09, 2 February 2024
Line 46:		Line 46:
	{{TAG\|LNABLA}},		{{TAG\|LNABLA}},
	{{TAG\|LEPSILON}},		{{TAG\|LEPSILON}},
	[[Time Evolution]]		[[Time Evolution]],
			{{TAG\|WPLASMAI}}

	See also: {{sc\|LOPTICS\|Examples\|Examples that use this tag}}		See also: {{sc\|LOPTICS\|Examples\|Examples that use this tag}}

← Older revision		Revision as of 08:43, 1 February 2024
Line 45:		Line 45:
	{{TAG\|CSHIFT}},		{{TAG\|CSHIFT}},
	{{TAG\|LNABLA}},		{{TAG\|LNABLA}},
	{{TAG\|LEPSILON}}		{{TAG\|LEPSILON}},
			[[Time Evolution]]

	See also: {{sc\|LOPTICS\|Examples\|Examples that use this tag}}~~, [[Time Evolution]]~~		See also: {{sc\|LOPTICS\|Examples\|Examples that use this tag}}

	== References ==		== References ==