AMIX MAG: Difference between revisions
(Created page with '{{TAGDEF|AMIX_MAG|[real]|1.6}} Description: {{TAG|AMIX_MAG}} linear mixing parameter for the magnetization density. ---- == Related Tags and Sections == {{TAG|IMIX}}, {{TAG|INI…') |
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Description: {{TAG|AMIX_MAG}} linear mixing parameter for the magnetization density. | Description: {{TAG|AMIX_MAG}} linear mixing parameter for the magnetization density. | ||
---- | ---- | ||
The default mixing parameters for spinpolarized calculations are: | |||
:{{TAG|IMIX}}=4, {{TAG|AMIX}}=0.4, {{TAG|AMIN}}=min(0.1,{{TAG|AMIX}},{{TAG|AMIX_MAG}}), {{TAG|BMIX}}=1.0, {{TAG|AMIX_MAG}}=1.6, and {{TAG|BMIX_MAG}}=1.0. | |||
These settings are consistent with an (initial) spin enhancement factor of 4, which is usually a reasonable approximation. | |||
There are only a few other parameter combinitions which can be tried, if convergence turns out to be very slow. In particular, for slabs, magnetic systems and insulating systems (e.g. molecules and clusters), an initial "linear mixing" can result in faster convergence than the Kerker model function.<ref name="kerker:prb:81"/> One can therefore try to use the following setting | |||
{{TAG|AMIX}} = 0.2 | |||
{{TAG|BMIX}} = 0.0001 ! almost zero, but 0 will crash some versions | |||
{{TAG|AMIX_MAG}} = 0.8 | |||
{{TAG|BMIX_MAG}} = 0.0001 ! almost zero, but 0 will crash some versions | |||
'''Mind''': For spinpolarized calculations the defaults for the mixing parameters {{TAG|AMIX}} and {{TAG|BMIX}} are different than for the non-spinpolarized case. | |||
== Related Tags and Sections == | == Related Tags and Sections == | ||
| Line 14: | Line 27: | ||
{{TAG|MIXPRE}}, | {{TAG|MIXPRE}}, | ||
{{TAG|WC}} | {{TAG|WC}} | ||
== References == | |||
<references> | |||
<ref name="kerker:prb:81">[http://link.aps.org/doi/10.1103/PhysRevB.23.3082 G. P. Kerker, Phys. Rev. B 23, 3082 (1981).]</ref> | |||
</references> | |||
---- | ---- | ||
[[The_VASP_Manual|Contents]] | [[The_VASP_Manual|Contents]] | ||
[[Category:INCAR]][[Category:Mixing]][[Category:Magnetism]] | [[Category:INCAR]][[Category:Mixing]][[Category:Magnetism]] | ||
Revision as of 14:51, 10 February 2011
AMIX_MAG = [real]
Default: AMIX_MAG = 1.6
Description: AMIX_MAG linear mixing parameter for the magnetization density.
The default mixing parameters for spinpolarized calculations are:
These settings are consistent with an (initial) spin enhancement factor of 4, which is usually a reasonable approximation.
There are only a few other parameter combinitions which can be tried, if convergence turns out to be very slow. In particular, for slabs, magnetic systems and insulating systems (e.g. molecules and clusters), an initial "linear mixing" can result in faster convergence than the Kerker model function.[1] One can therefore try to use the following setting
AMIX = 0.2 BMIX = 0.0001 ! almost zero, but 0 will crash some versions AMIX_MAG = 0.8 BMIX_MAG = 0.0001 ! almost zero, but 0 will crash some versions
Mind: For spinpolarized calculations the defaults for the mixing parameters AMIX and BMIX are different than for the non-spinpolarized case.
Related Tags and Sections
IMIX, INIMIX, MAXMIX, AMIX, BMIX, BMIX_MAG, AMIN, MIXPRE, WC