[Wien] Magnetic moments converging in a different direction to the one they are defined

[Lyudmila Dobysheva]

16.04.2019 12:29, Penny, Charles wrote:
> I am running spin-polarised calculations on a range of iron-spinel 
> structures (namely, magnetite (Fe3O4), maghemite (gamma-Fe2O3) and 
> greigite (Fe3S4)) with the objective of calculating magnetic exchange 
> energies in these minerals. This requires calculating total energies of 
> lot of different spinconfigurations. This process has worked well for 
> magnetite and maghemite, but I have encountered a problem with greigite.
> 
> When I run a calculation on a spin configuration of greigite that isn’t 
> the ferrimagnetic ground state (e.g. a ferromagnetic configuration) the 
> calculation converges to the ferrimagnetic solution, with the sublattice 
> moments pointing in opposing directions.

> When I define a ferrimagnetic spin configuration, the calculation 
> proceeds as expected, with the final moments looking like;
> rkmax_8_k_500.scf::ENE: ********** TOTAL ENERGY IN Ry =-43322.30312592
> k_500_rkmax_8.scf::ENE: ********** TOTAL ENERGY IN Ry =-43322.30312578

1. I'd like to add that the program can randomly miss second solution, 
better check it with some other initial magnetic structure.
2. For the Fe-Al system I obtained one or two solutions depending on the 
lattice parameter and Al concentration.

Best wishes
Lyudmila Dobysheva
------------------
Physics-Techn.Institute,
Udmurt Federal Research Center, Ural Br. of Rus.Ac.Sci.
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Russia
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