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

[Hongsheng Zhao]

Dear all,

I now doing some study on BaHfO_3 with uspp scheme.  The states
Ba 5s2 5p6 6s2, Hf 5d2 6s2 and O 2s2 2p4 were treated as valence
states.

I also found that following paper has done some researches on BaHfO_3:

http://dx.doi.org/10.1016/j.physleta.2008.04.015

In th 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? 

Sincerely yours,
-- 
Hongsheng Zhao <zhaohscas at yahoo.com.cn> 
Xinjiang Technical Institute of Physics and Chemistry
Chinese Academy of Sciences 
GnuPG DSA: 0xD108493
2008-8-21

__________________________________________________
¸Ï¿ì×¢²áÑÅ»¢³¬´óÈÝÁ¿Ãâ·ÑÓÊÏä?
http://cn.mail.yahoo.com