STM image simulation of spin-polarized calculation

marci marc... at
Tue May 1 09:02:36 CEST 2012

Dear Irene,

the behavior that you observe is obviously not apropriate.
This should not happen with metallic system. In that case the Fermi
is properly determined.
For systems with a gap the energy of the highest occupied state is
used as Fermi energy.
This is not optimal for STM simulations, and it needs a fix.
Thanks for reporting the problem.


On Apr 30, 6:40 pm, "Irene H." <hwyi... at> wrote:
> Dear All,
> While I'm working the STM image simulation of some spin-polarized systems,
> I notice that the Fermi energy is always the highest occupied state
> eigenvalue of the beta spin. If, for instance, I have a charged surface
> (semi-conductor with a band gap of ~3eV as neutral) with one excess
> electron in the gap on the alpha spin having an eigenvalue of E1, and the
> highest occupied state of the beta spin is still at the valence band top
> with an eigenvalue of E2 (E1 > E2). The program would however take E2,
> rather than E1 as the Fermi energy, which means if I'm calculating the
> empty state STM image, I will have to include the gap state, which is
> occupied.
> I'm wondering if there is someway to deal with this, or it doesn't matter.
> Best regards,
> Irene

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