The figure below illustrates a 2x2x1 supercell of transition metal-doped CrI$_3$ monolayer. The red, green, and black atoms represent Cr, I, and transition metal atoms, respectively. I want to calculate the energy of this doped monolayer in the AFM configuration, but I don't know how to set it. Please I need your urgent help on how to set the spins of the atoms for the AFM configuration for this doped monolayer. I mean which ones to set up, and which ones to set down? should I increase the supercell size?


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    $\begingroup$ I don't know for certain, but I would expect the AFM configuration to be such that neighbouring Cr/TM atoms have opposite spins, with a very small total net spin -- zero for a perfect AFM, but the presence of a TM other than Cr will probably change that. Is that what you meant? $\endgroup$ Jan 10, 2022 at 15:47
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    $\begingroup$ All I can find online is that the layers are ferromagnetic, with antiferromagnetic coupling between the layers. Is that what you meant? $\endgroup$ Jan 10, 2022 at 16:26
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    $\begingroup$ You can technically do this in ASE pretty easily. How do you currently run calculations? Manually construct INCAR? $\endgroup$ Jan 10, 2022 at 17:34
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    $\begingroup$ @TristanMaxson I think the question is more about which atoms are "up" and which are "down" $\endgroup$ Jan 10, 2022 at 19:25
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    $\begingroup$ @TristanMaxson I agree completely, it's very unlikely to be a perfect AFM if it's planar, with a non-Cr atom in there. I do think interlayer AFM is more likely though, and if this is really just a monolayer in this case, then there's nothing to simulate. $\endgroup$ Jan 10, 2022 at 20:28


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