[Pw_forum] highest occupied level is higher than the lowest unoccupied level in SCF!

[Paolo Giannozzi]

On Tue, Sep 29, 2015 at 7:45 PM, Zahra Taghipour <ztaghipour at unm.edu> wrote:

>
> This is semiconductor system with a band gap of about 215 meV!
> [...] However, the result of scf for the occupations is :
>       highest occupied, lowest unoccupied level (ev):     4.5710    3.9043
>
> Scf calculation converged without using smearing, but as you see highest
> occupied level is higher than the lowest unoccupied one!
>

so your semiconductor is not a semiconductor, it is a semimetal, at least
according to DFT. Never heard about the "band gap problem"?

Paolo

-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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