Generating Cu2+ ion on Cu100 slab with fractional occupation

[richard_kang]

Hello,

I am trying to generate Cu2+ ion adatom near a Cu(100) surface in charged environments, with a set NELECT value of non-integer number). I was wondering if this would be possible, and if so what would be the recommended protocols to get Cu2+.

So far, I have tried with ISPIN=2 tag (Since Cu2+ is an open-shell species, I am assuming I set ISPIN=2), and setting the MAGMOM tag, with initializing the magnetic moment of the Cu ion that I'd liked to have it as Cu2+ as 2.25 and rest relying on default setting (so 1's). I was using LORBIT=11 to check if I have Cu2+ in the end, but the magnetization value obtained at the end says all ions to be 0 so I am assuming this is not giving me Cu2+ in the end.

Any insights on this would be greatly appreciated! I am happy to provide POSCAR/INCAR/KPOINTS used but I am also utilizing a third-party code on top of it (VASPsol) so I am not sure if I can still have it here.

[alex]

Hi Richard,

well, there are two points to consider:
- numerically, you cannot force the desired atom to stay 2+ in a first-principles calculation.
- from a physics/chemistry view: why should there be an ion next to its metal(!) friends and stay without valence electrons?

Best regards,

alex