ENCUTGWSOFT: Difference between revisions

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


<math>\left( 1 + \mathbf{cos} \left( \pi \, \frac{ \frac{\hbar^{2} |\bold{G}|^2 }{2 m_e} - \mathbf{ENCUTGWSOFT}}{ \mathbf{TAG|ENCUTGW} -  \mathbf{TAG|ENCUTGWSOFT}} \right) \right)</math>  
<math>\left( 1 + \mathbf{cos} \left( \pi \, \frac{ \frac{\hbar^{2} |\bold{G}|^2 }{2 m_e} - \mathbf{ENCUTGWSOFT}}{ \mathbf{TAG|ENCUTGW} -  \mathbf{TAG|ENCUTGWSOFT}} \right) \right)</math>  

Revision as of 19:39, 15 January 2017

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

Default: ENCUTGWSOFT = ENCUTGW 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:

Related Tags and Sections

PRECFOCK, ENCUT, ENCUTGW, GW calculations


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