AMIX MAG: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 9: Line 9:
These settings are consistent with an (initial) spin enhancement factor of 4, which is usually a reasonable approximation.
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 combinations that 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.{{CITE|kerker:prb:1981}} One can therefore try to use the following setting  
There are only a few other parameter combinations that 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.{{cite|kerker:prb:1981}} One can therefore try to use the following setting  


  {{TAGBL|AMIX}}    = 0.2
  {{TAGBL|AMIX}}    = 0.2

Revision as of 08:19, 20 October 2023

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:

IMIX=4, AMIX=0.4, AMIN=min(0.1,AMIX,AMIX_MAG), BMIX=1.0, AMIX_MAG=1.6, and 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 combinations that 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 articles

IMIX, INIMIX, MAXMIX, AMIX, BMIX, BMIX_MAG, AMIN, MIXPRE, WC

Examples that use this tag

References

Cite error: <ref> tag with name "kerker:prb:81" defined in <references> is not used in prior text.