LTWO CENTER: Difference between revisions

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(Fix broken anchor (pointed to weighted method, not off-center interactions); {{Available|6.6.0}} (also fixes "Available of" typo); add VRijkl/URijkl to Related tags; Related tags spacing; remove ----/comment)
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{{TAGDEF|LTWO_CENTER|[logical]|.FALSE.}}
{{TAGDEF|LTWO_CENTER|[logical]|.FALSE.}}


Description: {{TAG|LTWO_CENTER}} calculates off-center [[Constrained–random-phase–approximation_formalism#Weighted_method_(w-cRPA)|Coulomb integrals]].  
Description: {{TAG|LTWO_CENTER}} calculates off-center [[Constrained–random-phase–approximation_formalism#Off-center_interactions|Coulomb integrals]].  
----
When chosen, the system calculates two types of integrals:
When chosen, the system calculates two types of integrals:


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U(R) = \frac{U(R=0)}{\sqrt{\frac{R}\delta + 1}}
U(R) = \frac{U(R=0)}{\sqrt{\frac{R}\delta + 1}}
</math>
</math>
{{NB|mind|Available of VASP version 6.6.0.}}
{{Available|6.6.0}}


== Related tags and articles==
== Related tags and articles ==
{{FILE|VRijkl}},
{{FILE|URijkl}},
{{TAG|LDISENTANGLED}},
{{TAG|LDISENTANGLED}},
{{TAG|LWEIGHTED}},
{{TAG|LWEIGHTED}},
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== References ==
== References ==
<references/>
<references/>
----


[[Category:INCAR_tag]][[Category:Constrained-random-phase approximation]]
[[Category:INCAR_tag]][[Category:Constrained-random-phase approximation]]
<!-- Link to categrories like this: [[Category:INCAR]][[Category:Constrained-random-phase approximation]] -->

Revision as of 09:17, 20 March 2026

LTWO_CENTER = [logical]
Default: LTWO_CENTER = .FALSE. 

Description: LTWO_CENTER calculates off-center Coulomb integrals. When chosen, the system calculates two types of integrals:

  • Bare integrals (stored in VRijkl)
[math]\displaystyle{ V_{ijkl}^{\sigma\sigma'} = \int {\rm d}{\bf r}\int {\rm d}{\bf r}' \frac{w_{i}^{*\sigma}({\bf r}) w_{j}^{\sigma}({\bf r}) w_{k}^{*\sigma'}({\bf r}'+{\bf R}) w_{l}^{\sigma'}({\bf r}'+{\bf R})}{|{\bf r}-{\bf r}'|} }[/math]
  • Effectively screened integrals (stored in URijkl)
[math]\displaystyle{ U_{ijkl}^{\sigma\sigma'} = \int {\rm d}{\bf r}\int {\rm d}{\bf r}' w_{i}^{*\sigma}({\bf r}) w_{j}^{\sigma}({\bf r}) U({\bf r},{\bf r}',\omega) w_{k}^{*\sigma'}({\bf r}'+{\bf R}) w_{l}^{\sigma'}({\bf r}'+{\bf R}) }[/math]

When chosen, cRPA matrix elements in vaspout.h5 can be used with py4vasp to analyze the spatial decay of the Coulomb interaction using the Ohno potential[1]

[math]\displaystyle{ U(R) = \frac{U(R=0)}{\sqrt{\frac{R}\delta + 1}} }[/math]

Mind: Available as of VASP 6.6.0

Related tags and articles

VRijkl, URijkl, LDISENTANGLED, LWEIGHTED, LSCRPA, ALGO

Howtos that use this tag

References