ENCUTGWSOFT: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
{{TAGDEF|ENCUTGWSOFT|[real]}} | {{TAGDEF|ENCUTGWSOFT|[real]}} | ||
{{DEF|ENCUTGWSOFT|{{TAG|ENCUTGW}}<math>\times 0.8</math>| for {{TAG|ALGO}}{{=}}''ACFDT''|{{TAG|ENCUTGW}}|else}} | {{DEF|ENCUTGWSOFT|{{TAG|ENCUTGW}}<math>\times 0.8</math>| for {{TAG|ALGO}}{{=}}''ACFDT''|{{TAG|ENCUTGW}}<math>\times 0.8</math>| as of VASP.6.3 | {{TAG|ENCUTGW}}|else}} | ||
For vasp.6.3 and later releases {{TAG|ENCUTGWSOFT}} always defaults to {{TAG|ENCUTGWS}}<math>\times 0.8</math>. | {{NB|important|For vasp.6.3 and later releases {{TAG|ENCUTGWSOFT}} always defaults to {{TAG|ENCUTGWS}}<math>\times 0.8</math>.}} | ||
Descprition: The flag {{TAG|ENCUTGWSOFT}} sets the energy cutoff for response function, such that it allows to truncate the Coulomb kernel slowly between the energy | Descprition: The flag {{TAG|ENCUTGWSOFT}} sets the energy cutoff for response function, such that it allows to truncate the Coulomb kernel slowly between the energy | ||
Revision as of 13:29, 22 November 2021
ENCUTGWSOFT = [real]
| Default: ENCUTGWSOFT | = ENCUTGW[math]\displaystyle{ \times 0.8 }[/math] | for ALGO=ACFDT |
| = ENCUTGW[math]\displaystyle{ \times 0.8 }[/math] | as of VASP.6.3 | |
| = ENCUTGW | else |
| Important: For vasp.6.3 and later releases ENCUTGWSOFT always defaults to ENCUTGWS[math]\displaystyle{ \times 0.8 }[/math]. |
Descprition: The flag ENCUTGWSOFT sets the energy cutoff for response function, such that it 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 ACFDT calculations and MP2 calculations. The modified Coulomb kernel is in this case: [math]\displaystyle{ v_{\bold{G}} = \frac{4 \pi e^2} {| \bold{G}|^2} \frac{1}{2} \left( 1 + \cos \left( \pi \, \frac{ \frac{\hbar^{2} |\bold{G}|^2 }{2 m_e} - \mathrm{ ENCUTGWSOFT} }{ \mathrm{ENCUTGW} - \mathrm{ENCUTGWSOFT}} \right) \right) \qquad \mbox{for} \quad \frac{\hbar^2 |\bold{G}|^2 }{2 m_e} > \mathrm{ENCUTGWSOFT} }[/math]
Related Tags and Sections
PRECFOCK, ENCUT, ENCUTGW, GW calculations