LSCRPA: Difference between revisions

From VASP Wiki
(Fix broken anchors (description pointed to wrong section; all 3 body anchors broken); {{Available|6.6.0}}; fix tautological opener; hyphenate method names; Related tags spacing; remove ----/comment)
(Blank lines: after description, after Available, before Related tags)
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
{{TAGDEF|LSCRPA|[logical]|.FALSE.}}
{{TAGDEF|LSCRPA|[logical]|.FALSE.}}


Description: {{TAG|LSCRPA}} selects the [[Constrained–random-phase–approximation_formalism#Spectral-cRPA_method_(s-cRPA)|spectral-cRPA method]].  
Description: {{TAG|LSCRPA}} selects the [[Constrained–random-phase–approximation_formalism#Spectral-cRPA_method_(s-cRPA)|spectral-cRPA method]].
 
{{Available|6.6.0}}
{{Available|6.6.0}}
In constrained random-phase approximation (cRPA) calculations, the target polarizability <math>\tilde\chi</math> is computed from the eigenspectrum of the target-space projectors as follows
In constrained random-phase approximation (cRPA) calculations, the target polarizability <math>\tilde\chi</math> is computed from the eigenspectrum of the target-space projectors as follows
::<math>\tilde  \chi^\sigma_{{\bf G,G}'}({\bf q},i\omega)\approx
::<math>\tilde  \chi^\sigma_{{\bf G,G}'}({\bf q},i\omega)\approx
Line 31: Line 33:


ordered according to their leverage scores. The s-cRPA method results in larger effective interactions compared to [[Constrained–random-phase–approximation_formalism#Weighted-cRPA_method_(w-cRPA)|w-cRPA]] or the [[Constrained–random-phase–approximation_formalism#Projector-cRPA_method_(p-cRPA)|projector-cRPA method]] and conserves the number of electrons.{{cite|kaltak:prb:2025}}
ordered according to their leverage scores. The s-cRPA method results in larger effective interactions compared to [[Constrained–random-phase–approximation_formalism#Weighted-cRPA_method_(w-cRPA)|w-cRPA]] or the [[Constrained–random-phase–approximation_formalism#Projector-cRPA_method_(p-cRPA)|projector-cRPA method]] and conserves the number of electrons.{{cite|kaltak:prb:2025}}
== Related tags and articles ==
== Related tags and articles ==
{{TAG|LDISENTANGLED}},
{{TAG|LDISENTANGLED}},
Line 36: Line 39:
{{TAG|ALGO}}
{{TAG|ALGO}}


{{sc|LSCRPA|Examples|Examples that use this tag}}
{{sc|LSCRPA|Howto|Workflows that use this tag}}


== References ==
== References ==

Latest revision as of 09:37, 20 March 2026

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

Description: LSCRPA selects the spectral-cRPA method.


Mind: Available as of VASP 6.6.0

In constrained random-phase approximation (cRPA) calculations, the target polarizability [math]\displaystyle{ \tilde\chi }[/math] is computed from the eigenspectrum of the target-space projectors as follows

[math]\displaystyle{ \tilde \chi^\sigma_{{\bf G,G}'}({\bf q},i\omega)\approx \frac 1{N_k}\sum_{nn'{\bf k}} \frac{ f_{n\bf k}-f_{n'\bf k-q} }{ \epsilon_{n{\bf k}} - \epsilon_{n'\bf k-q} - i \omega } \theta_{n\bf k }^{\sigma} \theta_{n'\bf k-p }^{\sigma'} \langle u_{n {\bf k }}^{\sigma } |e^{-i \bf (G+q) r}| u_{n'{\bf k-q}}^{ \sigma' } \rangle \langle u_{n' {\bf k-q}}^{\sigma' } |e^{-i \bf (G'-q)r'} | u_{n'{\bf k }}^{ \sigma } \rangle }[/math]

Here [math]\displaystyle{ \theta_{n{\bf k}}^\sigma }[/math] are the eigenvalues of the correlated projectors

[math]\displaystyle{ P_{mn}^{\sigma({\bf k})} = \sum_{i\in \cal T} T_{i m}^{*\sigma({\bf k})} T_{i n}^{\sigma({\bf k})} }[/math]

ordered according to their leverage scores. The s-cRPA method results in larger effective interactions compared to w-cRPA or the projector-cRPA method and conserves the number of electrons.[1]

Related tags and articles

LDISENTANGLED, LWEIGHTED, ALGO

Workflows that use this tag

References