Dear Siesta Users,
I did some calculations for 4x4 graphene
doped with nitrogen. when I was doing the optimization (cell parameters and
atomic position) I found two solutions. One of the correspond has a net
magnetic moment of 1 uB ( 65 spin up and 64 spin down). The other minima has
zero magnetic moment (Qup 64.5 and Qdown 64.5). The latter is about 1 eV
lower in energy and the structures are not that different.
I have seen this problem in DFT anf HF calculations for open shell molecules
with strong spin contamination, but what is confusing me is that the
wavefunciton with zero magnetic moment is lower in energy. I would expect
the opposite situation based on the results for molecules.
I would like to know if somebody faced the same situation or knows have
understand it.
Many thanks...
Best regards,
Pablo
