LSCK: Difference between revisions

Revision as of 17:01, 21 December 2021

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

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

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

${\displaystyle v_{G} = 4 \pi e^2 \frac{ (G_{max}-G_{min})(G_{max}-G) }{ (G_{min}^2 - G(2G_{min}-G_{max}))^2 } \qquad \mbox{for} \quad \mathrm{ENCUTGWSOFT}=\frac{\hbar^2G_{min}^2}{2m_e}<\frac{\hbar^2 G^2}{2m_e}<\frac{\hbar^2G_{max}^2}{2m_e}=\mathrm{ENCUTGW}}$

This kernel 'squeezes' the contributions from large wave vectors $G>G_{max}$ into the window given by ENCUTGWSOFT. Effectively, this extrapolates the random-phase-approximation–correlation energy to the ENCUTGW $\to \infty$ limit, assuming that the basis-set-incompleteness error falls off as $1/$ ENCUTGW $^{3/2}$ .

@@ Line 12: / Line 12: @@
 \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' 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>.
+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|GW calculations}}