Dear Siesta users
I have had a problem for a long time and I sincerely hope you can help me. I was working on a 4 x 4 graphene sheet doped with an iron atom. By optimizing the structure, the system converges to two configurations. One of them is magnetic (1.98540 muB - 66.993 spin up and 65.007 - Etot = -5392.163850 eV) and the other is non-magnetic (0 muB - 66 spin up and 66 spin down - Etot = -5391.862081 eV). According to some articles, it would be expected that the most stable structure is the non-magnetic configuration (https://pubs.acs.org/doi/abs/10.1021/jp911535v, https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.102.126807). But from what I can observe from my calculations is that the magnetic structure corresponds to a lower total energy. Increase the size of the super cell to 5x5 but got no different results. What I can do? I need some help.
Hugo Cabrera-Tinoco Post-doctoral research Universidad Nacional Mayor de San Marcos Lima-Perú
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
