Dear colleagues,

I have some confusion on building DM.InitSpin block for magnetic systems. I
was hoping if someone could guide me through this, that would be highly

I am working on FM systems and I have noticed that using these two blocks
(below) give the same result.

%block DM.InitSpin      # this polarizes along z-axis
 5   +   0.  0.
 6   +   0.  0.
%endblock DM.InitSpin

%block DM.InitSpin       # this polarizes along x-axis
 5   +   90.  0.
 6   +   90.  0.
%endblock DM.InitSpin

My system has easy-plane type magnetic anisotropy means in the ab plane
magnetization is strong and along z-axis it is weak.

When I calculate spin density and pDOS for these two spin polarized
directions, I get exactly the same results.  It seems to me for any given
direction full saturation moment is taken.

Does it mean that Siesta considers it as isotropic system and independent of
polarization directions? Is there any way to check the final direction of
magnetic moment?

However, in my system anisotropy comes from the sing-ion anisotropy(SIA) and
this SIA is not included in the calculation. Therefore, it make sense that
SIESTA takes it as isotropic. Is it so?

Could someone please help me to understand this situation? Is there any way to
include such SIA or magnetic exchange interactions in the input file?

Best regards,
SIESTA is supported by the Spanish Research Agency (AEI) and by the European 
H2020 MaX Centre of Excellence (

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