ENCUTGWSOFT: Difference between revisions

Revision as of 19:30, 15 January 2017

ENCUTGWSOFT = [real] (energy cutoff for response function)

Default: ENCUTGWSOFT	= ENCUTGW $\times 0.8$	for ALGO=ACFDT
	= ENCUTGW	else

The flag allows to truncate the Coulomb kernel slowly between the energy specified by ENCUTGWSOFT and ENCUTGW. This usually leads to much smoother energy-volume curves in AC-FDT and MP2 calculations. The modified Coulomb kernel is in this case: ${\displaystyle v_{\bold{G}} = \frac{4 \pi e^2} {| \bold{G}|^2} \frac{1}{2} \left( 1 + {\rm cos} \left( \pi \, \frac{ \frac{\hbar^2 |\bf G|^2 }{2 m_e} - {{TAG|ENCUTGWSOFT}}}{ {{TAG|ENCUTGW}} - {{TAG|ENCUTGWSOFT}}} \right) \right) \qquad \mbox{for} \quad \frac{\hbar^2 |\bf G|^2 }{2 m_e} > {{TAG|ENCUTGWSOFT}}}$

$v_{\bold{G}} \frac{4 \pi e^2} {| \bold{G}|^2}$

Related Tags and Sections

PRECFOCK, ENCUT, ENCUTGW, GW calculations

Contents

@@ Line 8: / Line 8: @@
 This  usually leads to much smoother energy-volume curves in AC-FDT and MP2 calculations.
 The modified Coulomb kernel is in this case:
-<math>v_{\bf G} = \frac{4 \pi e^2} {| \bf G|^2} \frac{1}{2} \left( 1 + {\rm cos} \left( \pi \, \frac{ \frac{\hbar^2 |\bf G|^2 }{2 m_e} - {{TAG|ENCUTGWSOFT}}}{ {{TAG|ENCUTGW}} -  {{TAG|ENCUTGWSOFT}}} \right) \right)
+<math>v_{\bold{G}} = \frac{4 \pi e^2} {| \bold{G}|^2} \frac{1}{2} \left( 1 + {\rm cos} \left( \pi \, \frac{ \frac{\hbar^2 |\bf G|^2 }{2 m_e} - {{TAG|ENCUTGWSOFT}}}{ {{TAG|ENCUTGW}} -  {{TAG|ENCUTGWSOFT}}} \right) \right)
 \qquad \mbox{for} \quad  \frac{\hbar^2 |\bf G|^2 }{2 m_e} >  {{TAG|ENCUTGWSOFT}}</math>
-<math>v_{\bold{G}} </math>
+<math>v_{\bold{G}} \frac{4 \pi e^2} {| \bold{G}|^2}</math>
 == Related Tags and Sections ==
 {{TAG|PRECFOCK}},