Surface states in ATK-SE

[Dhirendra]

Hi,

I am trying to use the ATK-SE to simulate the Silicon/Germanium slab with some vacuum. I am not passivating the slab so that I get surface states, this happens with DFT. But with ATK-SE I am seeing a bandgap in DOS at surface atoms. Am I missing any physical aspect there?

[Anders Blom]

If you make a non-selfconsistent calculation there will not be any charge transfer, and thus no surface states. If you include selfconsistency then you have to add H atoms (or some other surface passivation) also for TB models.