next up previous contents
Next: 7.10 ISTART-tag Up: 7 The INCAR File Previous: 7.8 ISPIN-tag

7.9 MAGMOM-tag

 

Default 1
Specifies the initial magnetic moment per atom. If you are looking for a ferromagnetic solution, it is usually safest to start from a large value, in some cases the default value might not be sufficient.

Antiferro magnetic calculations require a somewhat more tricky setup, because at present VASP does not check whether the initial magnetic moments break the symmetry. The simplest way to break the symmetry is by using two different species. A POSCAR file for AF Cr would be:

Cr: AF
 2.80000
  1.00000   .00000   .00000
   .00000  1.00000   .00000
   .00000   .00000  1.00000
  1 1
Kartesisch
   .00000   .00000   .00000
   .50000   .50000   .50000
and the INCAR file should have a line
 MAGMOM = 1 -1
The POTCAR file should of course also contain the Cr PP twice. (in one of the next VASP releases this problem will be fixed, i.e. VASP will check which symmetry opertation have to be removed



MASTER USER VASP
Mon Mar 29 10:38:29 MEST 1999