LNABLA - Revision history

Huebsch at 14:27, 19 July 2022

2022-07-19T14:27:48Z

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

	[[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 */

2022-07-19T07:58:51Z

References

← Older revision		Revision as of 07:58, 19 July 2022
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	----		----

	[[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: /* Related Tags and Sections */

2022-04-08T14:36:49Z

Related Tags and Sections

← Older revision		Revision as of 14:36, 8 April 2022
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	Except for the purpose of testing, there is however hardly ever a reason		Except for the purpose of testing, there is however hardly ever a reason
	to use the transversal expression, since it is less accurate.		to use the transversal expression, since it is less accurate.
	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|LOPTICS}},		{{TAG\|LOPTICS}},
	{{TAG\|CSHIFT}}		{{TAG\|CSHIFT}}

Karsai at 14:36, 8 April 2022

2022-04-08T14:36:43Z

← Older revision		Revision as of 14:36, 8 April 2022
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	</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 at 14:00, 8 March 2019

2019-03-08T14:00:40Z

← Older revision		Revision as of 14:00, 8 March 2019
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	[[The_VASP_Manual\|Contents]]		[[The_VASP_Manual\|Contents]]

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

Karsai at 14:06, 21 February 2019

2019-02-21T14:06:28Z

← Older revision		Revision as of 14:06, 21 February 2019
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	[[The_VASP_Manual\|Contents]]		[[The_VASP_Manual\|Contents]]

	[[Category:INCAR]][[Category:~~Static~~ dielectric properties]]		[[Category:INCAR]][[Category:Frequency dependent dielectric properties]]

Karsai at 15:23, 20 February 2019

2019-02-20T15:23:39Z

← Older revision		Revision as of 15:23, 20 February 2019
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	[[The_VASP_Manual\|Contents]]		[[The_VASP_Manual\|Contents]]

	[[Category:INCAR]][[Category:~~Linear response~~]]		[[Category:INCAR]][[Category:Static dielectric properties]]

Karsai at 10:19, 20 March 2017

2017-03-20T10:19:11Z

← Older revision		Revision as of 10:19, 20 March 2017
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	{{TAG\|LOPTICS}},		{{TAG\|LOPTICS}},
	{{TAG\|CSHIFT}}		{{TAG\|CSHIFT}}

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

	== References ==		== References ==

Mmars: Created page with '{{TAGDEF|LNABLA|.TRUE. {{!}} .FALSE.|.FALSE.}} Description: {{TAG|LNABLA}}=.TRUE. evaluates the transversal expression for the frequency dependent dielectric matrix. ---- Usuall…'

2011-02-18T15:11:22Z

Created page with '{{TAGDEF|LNABLA|.TRUE. {{!}} .FALSE.|.FALSE.}} Description: {{TAG|LNABLA}}=.TRUE. evaluates the transversal expression for the frequency dependent dielectric matrix. ---- Usuall…'

New page

{{TAGDEF|LNABLA|.TRUE. {{!}} .FALSE.|.FALSE.}}

Description: {{TAG|LNABLA}}=.TRUE. evaluates the transversal expression for the frequency dependent dielectric matrix.
----
Usually VASP uses the [[LOPTICS#epsilon|longitudinal expression for the frequency dependent dielectric matrix]].
It is however possible to switch to the computationally somewhat simpler transversal expressions by selecting {{TAG|LNABLA}}=.TRUE. (Eqs. 17 and 20 in Ref.<ref name="gajdos:prb:06"/>).
In this simplification the imaginary part of the macroscopic dielectric function is given by

:<math>
\epsilon^{(2)}_{\alpha \beta} (\omega) = \frac{4 \pi^2 e^2 \hbar^4}{\Omega \omega^2 m_e^2}
\mathrm{lim}_{\mathbf{q} \rightarrow 0} \sum_{c,v, \mathbf{k}} 2 w_\mathbf{k}
\delta( \epsilon_{c\mathbf{k+q}} - \epsilon_{v\mathbf{k}} - \omega)
\times \langle u_{c\mathbf{k}} | i{\mathbf{\nabla}_{\alpha} - \mathbf{k}}_{\alpha} | u_{v\mathbf{k}} \rangle
\langle u_{c\mathbf{k}} | i{\mathbf{\nabla}_{\beta} - \mathbf{k}}_{\beta} | u_{v\mathbf{k}} \rangle^*.
</math>

Except for the purpose of testing, there is however hardly ever a reason
to use the transversal expression, since it is less accurate.
== Related Tags and Sections ==
{{TAG|LOPTICS}},
{{TAG|CSHIFT}}

== References ==
<references>
<ref name="gajdos:prb:06">[http://link.aps.org/doi/10.1103/PhysRevB.73.045112 M. Gajdoš, K. Hummer, G. Kresse, J. Furthmüller, and F. Bechstedt, Phys. Rev. B 73, 045112 (2006).]</ref>
</references>
----
[[The_VASP_Manual|Contents]]

[[Category:INCAR]][[Category:Linear response]]