ENCUTGWSOFT: Difference between revisions
No edit summary |
No edit summary |
||
| Line 13: | Line 13: | ||
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_{\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} - {\tt ENCUTGWSOFT}}{ {\tt ENCUTGW - ENCUTGWSOFT}} \right) \right) | 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} - {\tt ENCUTGWSOFT}}{ {\tt ENCUTGW - ENCUTGWSOFT}} \right) \right) | ||
\qquad \mbox{for} \quad \frac{\hbar^2 |\bf G|^2 }{2 m_e} > {\tt ENCUTGWSOFT} | \qquad \mbox{for} \quad \frac{\hbar^2 |\bf G|^2 }{2 m_e} > {\tt ENCUTGWSOFT}</math> | ||
Revision as of 17:26, 15 January 2017
ENCUTGWSOFT = [real] (energy cutoff for response function)
Default: ENCUTGWSOFT = ENCUTGW for ALGO=ACFDT
\begin{tabular} {ll}
Default: \\
{\tt ENCUTGWSOFT}={\tt ENCUTGW}$\times 0.8$ & for {\tt ALGO}=ACFDT \\
{\tt ENCUTGWSOFT}={\tt ENCUTGW} & else \\
\end{tabular}
\vspace{5mm}
The flag allows to truncate the Coulomb kernel slowly between the energy specified by {\tt ENCUTGWSOFT} and {\tt ENCUTGW}. This usually leads to much smoother energy-volume curves in AC-FDT and MP2 calculations. The modified Coulomb kernel is in this case: Failed to parse (unknown function "\tt"): {\displaystyle 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} - {\tt ENCUTGWSOFT}}{ {\tt ENCUTGW - ENCUTGWSOFT}} \right) \right) \qquad \mbox{for} \quad \frac{\hbar^2 |\bf G|^2 }{2 m_e} > {\tt ENCUTGWSOFT}}
Related Tags and Sections
PRECFOCK, ENCUT, ENCUTGW, GW calculations