LSCK: Difference between revisions

From VASP Wiki
No edit summary
 
(6 intermediate revisions by 3 users not shown)
Line 1: Line 1:
{{TAGDEF|LSCK|[logical]| .FALSE.}}
{{TAGDEF|LSCK|[logical]| .FALSE.}}                           
----
{{NB|important|Up to vasp.6.2, the default was {{TAG|LSCK}}{{=}} .TRUE.}}
If {{TAG|LSCK}} is set to .TRUE., the squeezed Coulomb kernel is used instead of the [[ENCUTGWSOFT|cosine window]]:{{cite|riemelmoser:jcp:2020}}
----Description: {{TAG|LSCK}}=.True. switches on the squeezed Coulomb kernel.
If {{TAG|LSCK}} is set to .TRUE., the squeezed Coulomb kernel is used instead of the [[ENCUTGWSOFT|cosine window]] {{cite|riemelmoser:jcp:2020}}:


<math>v_{G} = 4 \pi e^2 \frac{
<math>v_{G} = 4 \pi e^2 \frac{
Line 10: Line 11:
\qquad \mbox{for} \quad  \mathrm{ENCUTGWSOFT}=\frac{\hbar^2G_{min}^2}{2m_e}<\frac{\hbar^2 G^2}{2m_e}<\frac{\hbar^2G_{max}^2}{2m_e}=\mathrm{ENCUTGW}</math>  
\qquad \mbox{for} \quad  \mathrm{ENCUTGWSOFT}=\frac{\hbar^2G_{min}^2}{2m_e}<\frac{\hbar^2 G^2}{2m_e}<\frac{\hbar^2G_{max}^2}{2m_e}=\mathrm{ENCUTGW}</math>  


This kernel ''squeezes'' contributions from large wave vectors <math>G>G_{max}</math> into the window given by {{TAGBL|ENCUTGWSOFT}}. Effectively, this extrapolates the RPA correlation energy to the {{TAG|ENCUTGW}} <math>\to \infty</math> limit, assuming that the basis set incompleteness error falls off as <math>1/\mathrm{ENCUTGW}^{3/2}</math>.
This kernel 'squeezes' the contributions from large wave vectors <math>G>G_{max}</math> into the window given by {{TAG|ENCUTGWSOFT}}. Effectively, this extrapolates the random-phase-approximation&ndash;correlation energy to the {{TAG|ENCUTGW}} <math>\to \infty</math> limit, assuming that the basis-set-incompleteness error falls off as <math>1/</math>{{TAG|ENCUTGW}}<math>^{3/2}</math>.
== Related Tags and Sections ==
== Related tags and articles ==
{{TAG|ENCUTGW}},
{{TAG|ENCUTGW}},
{{TAG|GW calculations}}
{{TAG|GW calculations}}
Line 18: Line 19:
{{sc|LSCK|Examples|Examples that use this tag}}
{{sc|LSCK|Examples|Examples that use this tag}}
----
----
[[The_VASP_Manual|Contents]]


[[Category:INCAR]][[Category:Many-Body Perturbation Theory]][[Category:GW]][[Category:ACFDT]]
[[Category:INCAR tag]][[Category:Many-body perturbation theory]][[Category:GW]][[Category:ACFDT]]

Latest revision as of 08:41, 29 August 2024

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

Important: Up to vasp.6.2, the default was LSCK= .TRUE.

Description: LSCK=.True. switches on the squeezed Coulomb kernel.

If LSCK is set to .TRUE., the squeezed Coulomb kernel is used instead of the cosine window [1]:

This kernel 'squeezes' the contributions from large wave vectors into the window given by ENCUTGWSOFT. Effectively, this extrapolates the random-phase-approximation–correlation energy to the ENCUTGW limit, assuming that the basis-set-incompleteness error falls off as ENCUTGW.

Related tags and articles

ENCUTGW, GW calculations ACFDT/RPA calculations

Examples that use this tag