[Pw_forum] The corresponding electronic state of the band gap.

[Paolo Giannozzi]

Hongsheng Zhao wrote:

> In the abstract of the above paper, the authors said:
> 
> -----------------
> Band structures show that BaHfO3 is a direct band gap between the occupied O 2p and unoccupied Hf d states.
> -----------------
> 
> I just want to know how to decide the O 2p and Hf 5d as the the occupied and the unoccupied states corresponding to the band gap?
> In detail, in the above computation, the p states are comes from Ba and O simultaneously, so why can they only said the O 2p? 

the above statement just means that the top of the valence band
is mainly composed of O 2p states, while the bottom of the
conduction band is mainly composed of Hf 5d states. You can
easily check if this is true  using code 'projwfc.x'.

Disclaimed: I am not sure I understood what you mean,
and I know nothing about BaHfO3

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy