Dear all:
My PW nscf calculations report that "highest occupied, lowest unoccupied level (ev): 25.9823 25.9261". However, the setup of yambo gives me that"
Fermi Level [ev]: 5.671248
Electronic Temp. [ev K]: 0.00 0.00
Bosonic Temp. [ev K]: 0.00 0.00
El. density [cm-3]: 0.422E+24
States summary : Full Metallic Empty
0001-0108 0109-0500
Indirect Gaps [ev]: 6.297390 6.347350
Direct Gaps [ev]: 6.321119 6.999879
"
my system is under high temperature about 8000K, but the temp reported is 0. Besides, the Fermi level is far more different with that of pw calculations. Why?
wrong Fermi level??
Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, Daniele Varsano
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wrong Fermi level??
Shijun Zhao
College of Engineering
Peking University
College of Engineering
Peking University
- Daniele Varsano
- Posts: 3838
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: wrong Fermi level??
Dear Shijun,
It is very hard to help you if you do not post some useful informations, as yambo report files and Pwscf outputs.
Best,
Daniele
It is very hard to help you if you do not post some useful informations, as yambo report files and Pwscf outputs.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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- Posts: 26
- Joined: Wed Aug 27, 2014 8:09 am
Re: wrong Fermi level??
Daniele Varsano wrote:Dear Shijun,
It is very hard to help you if you do not post some useful informations, as yambo report files and Pwscf outputs.
Best,
Daniele
Please see the attachment. I have used the occupation_fix options. Maybe it is the problem? If I do not use this option, everything goes well.
Last edited by zsjan on Sun Dec 28, 2014 1:38 pm, edited 1 time in total.
Shijun Zhao
College of Engineering
Peking University
College of Engineering
Peking University
- Daniele Varsano
- Posts: 3838
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: wrong Fermi level??
Dear Shijun,
next time please use the upload button to post files as with copy-paste is very hard then to read them.
Yes the problem as you argue is that you used the occupation_fixed options. If you use for instance the occupations='smearing' option the electronic temperature will be then read by yambo and used to calculate the Fermi level. Yambo do recalculate occupations and Femi level, and in this case this was done as at 0K temperature.
Other option would be to add the ElecTemp variable in your setup input file. But I suggest the first method as you are sure everything is consistent.
Best,
Daniele
next time please use the upload button to post files as with copy-paste is very hard then to read them.
Yes the problem as you argue is that you used the occupation_fixed options. If you use for instance the occupations='smearing' option the electronic temperature will be then read by yambo and used to calculate the Fermi level. Yambo do recalculate occupations and Femi level, and in this case this was done as at 0K temperature.
Other option would be to add the ElecTemp variable in your setup input file. But I suggest the first method as you are sure everything is consistent.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
-
- Posts: 26
- Joined: Wed Aug 27, 2014 8:09 am
Re: wrong Fermi level??
Daniele Varsano wrote:Dear Shijun,
next time please use the upload button to post files as with copy-paste is very hard then to read them.
Yes the problem as you argue is that you used the occupation_fixed options. If you use for instance the occupations='smearing' option the electronic temperature will be then read by yambo and used to calculate the Fermi level. Yambo do recalculate occupations and Femi level, and in this case this was done as at 0K temperature.
Other option would be to add the ElecTemp variable in your setup input file. But I suggest the first method as you are sure everything is consistent.
Best,
Daniele
Thank you very much. So how the yambo recalculate the occupations and Fermi level? Is this according to Fermi-dirac distribution or something?
If I want to assign certain occupations to initialize the calculations, what can i do to acheive this?
Shijun Zhao
College of Engineering
Peking University
College of Engineering
Peking University
- Daniele Varsano
- Posts: 3838
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: wrong Fermi level??
Yes, they are calculated according to the Fermi-Dirac distribution.. So how the yambo recalculate the occupations and Fermi level? Is this according to Fermi-dirac distribution or something?
What you can do, is to play with electronic temperature, but you cannot fix occupations by hand.If I want to assign certain occupations to initialize the calculations, what can i do to acheive this?
Hope it helps,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/