[Wien] two different GAP value in a scf-iteration

[Ong Phuong Khuong (IHPC)]

I believe that there is no gap in your case. It is just simply one (GAP) for spin up and one (no GAP) for spin down.

=======================================================

 Dr. Khuong P. Ong

 Research Scientist

 Optics and Transport (Team Leader)

 Materials Science & Engineering Department

 Institute of High Performance Computing

 1 Fusionopolis Way, #16-16, Connexis, Singapore 138632

 Mob:      +65. 81885057
 Tel(Off): +65. 64191566
 Fax:      +65. 64632536

=======================================================



-----Original Message-----
From: wien-bounces at zeus.theochem.tuwien.ac.at [mailto:wien-bounces at zeus.theochem.tuwien.ac.at] On Behalf Of hiroshi.nakano at sharp.co.jp
Sent: Friday, October 05, 2012 9:32 AM
To: wien at zeus.theochem.tuwien.ac.at
Subject: [Wien] two different GAP value in a scf-iteration

Dear Prof Blaha and wien2k users,

I have a problem in understanding case.scf files due to two different :GAP values in each SCF iteration.

I am trying to calculate electron states in Europium doped oxides and sulfides using the supercell method and spin-polarized GGA(+U) functional.
SCF calculation and geometry optimization converge and reproduce the experimentally appropriate magnetic moments successfully.

But I found all of the compounds has two bandgap parameters in a SCF-iteration including the converged last iteration.

The case.scf file has two :GAP values and one :ENE value in each SCF-iterations.
Moreover, using DFT+U or increasing k-points don't change the situation.

The questions are:
(1)Should I believe the positive bandgap value which is reasonable for the experimental results?
(2)What do the negative :GAP values mean?
(3)What is the recommendation to solve this problem if I should?

Please tell me if you need more information to find the way to get through.

-------------------------------------------------------------
The results of the analysis of case.scf file:
grep :ENE basioneu03.scf:
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70594742
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70642208
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70633306
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70631446
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70627735
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70622835
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70620029
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70623923
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70624546
:ENE  : ********** TOTAL ENERGY IN Ry =      -222804.70625225

grep :GAP case.scf:
:GAP  :    0.0293 Ry =     0.399 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0059 Ry =    -0.080 eV   (provided you have a proper k-mesh)
:GAP  :    0.0293 Ry =     0.398 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0058 Ry =    -0.079 eV   (provided you have a proper k-mesh)
:GAP  :    0.0289 Ry =     0.394 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
:GAP  :    0.0287 Ry =     0.390 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0056 Ry =    -0.076 eV   (provided you have a proper k-mesh)
:GAP  :    0.0288 Ry =     0.392 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0056 Ry =    -0.076 eV   (provided you have a proper k-mesh)
:GAP  :    0.0291 Ry =     0.396 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
:GAP  :    0.0292 Ry =     0.397 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
:GAP  :    0.0292 Ry =     0.397 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
:GAP  :    0.0291 Ry =     0.396 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
:GAP  :    0.0291 Ry =     0.396 eV   (provided you have a proper k-mesh)
:GAP  :   -0.0057 Ry =    -0.077 eV   (provided you have a proper k-mesh)
---------------------------------------------------------------------------

Regards,
Hiroshi Nakano

_______________________________________________
Wien mailing list
Wien at zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

IHPC Values  ::  Impact   ::   Honesty   ::   Performance   ::   Co-operation
This email is confidential and may be privileged. If you are not the intended recipient, please delete it and notify us immediately. Please do not copy or use it for any purpose, or disclose its contents to any other person. Thank you.