[Wien] MBJ, case.in0_grr

shima pourrad shima.pourrad at gmail.com
Wed Dec 16 07:05:12 CET 2015


Dear F.Tran

I appreciate a lot because of your explanation. I ran the calculations with
-ec 0.00001 convergence criteria. But unfortunately I found that I made a
bad mistake : for the second calculation I forgot to change the mixing
scheme to PRRAT , and it ran with the default mixing scheme which is MSR1.
And this mistake causes two different results.(When I corrected mixing
scheme , both calculations gave me the same results ). I apologize because
of this carelessness.

So I have another question, which of the two mixing schemes gives me
reliable results? I mean, is it possible my first calculation (with PRRAT
and mixing factor=0.2) converged to the ghost band??  In user guide it was
written that: in most cases it is possible to switch back to MSR1 after
some initial scf-cycles. Can we use MSR1 from the first of the calculation?
What kind of mixing scheme we can use for the mbj calculations?

Thanks a lot.

Shima M.pourrad

On Mon, Dec 14, 2015 at 7:39 PM, <tran at theochem.tuwien.ac.at> wrote:

> For the moment, I suspect that your calculations are not very well
> converged. Did you run the calculations with good energy and charge
> convergence criteria? If not, run the two calculations with
> -ec 0.0001 -cc 0.0001
> which is fairly good criteria. Then, maybe the two calculations
> give same results.
>
>
>
> On Mon, 14 Dec 2015, shima pourrad wrote:
>
>
>> Hi
>>
>> Thanks for your prompt answer.
>>
>> Yes, for the first calculation with “ EX_GRR VX_GRR” I have :
>>
>> Case.in0 :
>>
>> TOT  XC_MBJ
>> (XC_LDA,XC_PBESOL,XC_WC,XC_MBJ,XC_REVTPSS)
>>
>> R2V      IFFT      (R2V)
>>
>>  120 120 120    1.00  1    min IFFT-parameters, enhancement factor, iprint
>>
>>
>>
>> And case.in0_grr :
>>
>> TOT  EX_GRR VX_GRR
>> (XC_LDA,XC_PBESOL,XC_WC,XC_MBJ,XC_REVTPSS)
>>
>> R2V      IFFT      (R2V)
>>
>>  120 120 120    1.00  1    min IFFT-parameters, enhancement factor, iprint
>>
>>
>>
>>  This calculation give me these results by Analysis :
>>
>> --- ENE -----------
>>
>> in  1 files:
>>
>> case.scf::ENE  : *WARNING** TOTAL ENERGY IN Ry =       -79386.93188247
>>
>> --- FER -----------
>>
>> in  1 files:
>>
>> case.scf::FER  : F E R M I - ENERGY(TETRAH.M.)=   0.4117108915
>>
>> --- GAP -----------
>>
>> in  1 files:
>>
>> case.scf::GAP  :    0.0564 Ry =     0.767 eV   (provided you have a
>> proper k-mesh)
>>
>>
>>
>> For the second calculation with “ EX_GRR EC_NONE VX_GRR VC_NONE” I have:
>>
>> Case.in0 :
>>
>> TOT   XC_MBJ (
>> (XC_LDA,XC_PBESOL,XC_WC,XC_MBJ,XC_REVTPSS)
>>
>> R2V      IFFT      (R2V)
>>
>>  120 120 120    1.00  1    min IFFT-parameters, enhancement factor, iprint
>>
>>
>>
>> And case.in0_grr :
>>
>> TOT   EX_GRR EC_NONE VX_GRR VC_NONE (
>> (XC_LDA,XC_PBESOL,XC_WC,XC_MBJ,XC_REVTPSS)
>>
>> R2V      IFFT      (R2V)
>>
>>  120 120 120    1.00  1    min IFFT-parameters, enhancement factor, iprint
>>
>>
>>
>>
>>
>> And its results :
>>
>> --- ENE -----------
>>
>> in  1 files:
>>
>> case.scf::ENE  : *WARNING** TOTAL ENERGY IN Ry =       -79386.93585459
>>
>> --- FER -----------
>>
>> in  1 files:
>>
>> case.scf::FER  : F E R M I - ENERGY(TETRAH.M.)=   0.4269866858
>>
>> --- GAP -----------
>>
>> in  1 files:
>>
>> case.scf::GAP  :    0.0423 Ry =     0.575 eV   (provided you have a
>> proper k-mesh)
>>
>>
>>
>> what is your opinion?
>>
>> Sincerely
>>
>> Shima M.Pourrad
>>
>>
>> On Mon, Dec 14, 2015 at 6:11 PM, <tran at theochem.tuwien.ac.at> wrote:
>>       Hi,
>>
>>       "XC_MBJ" in the 1st line of case.in0 indicates that the mBJ method
>>       will be used. For mBJ, it is necessary to have also the file
>> case.in0_grr
>>       such that the average of grad(rho)/rho in the unit cell
>>       [used for Eq. (3) in PRL 102, 226401 (2009)] is calculated.
>>
>>       According to a test that I've just made it does not matter which one
>>       of these two is specified in case.in0_grr:
>>       "EX_GRR EC_NONE VX_GRR VC_NONE"
>>       "EX_GRR VX_GRR"
>>
>>       So, I don't understand why you got two different results.
>>       Can you show us the input files case.in0 and case.in0_grr
>>       that you used for the two calculations?
>>
>>       F. Tran
>>
>>       On Mon, 14 Dec 2015, shima pourrad wrote:
>>
>>
>>             Dear P.Blaha and F.Tran and Wien2k Users
>>
>>             I am running wien version14.2 .The purpose of my calculations
>> is to get accurate gap and band structure. Hence I am performing MBJ
>> calculations with the parameters special to semiconductors.
>>
>>             I would like to ask how we should edit case.in0_grr for a mbj
>> calculation in wien2k14.2 ?
>>
>>             I read the user guide and checked the mailing list before, I
>> didn’t find any obvious instruction.
>>
>>             In user guide, it was written that: when you perform
>> init_mbj_lapw for the second time, some steps must do automatically:
>>
>>              *
>>                 edit case.in0 and change the functional to option XC_MBJ.
>> (ok this step is done).
>>
>>              *
>>                  cp case.in0 case.in0_grr and choose EX_GRR VX_GRR in
>> case.in0_grr.
>>
>>             But this step, when I open the case.in0_grr to check that, at
>> first line, it was written that: EX_GRR EC_NONE VX_GRR VC_NONE. Is it a
>> correct edition? Should I remove “EC_NONE VC_NONE” from the first line?
>>
>>             I think “EX_GRR EC_NONE VX_GRR VC_NONE” means that
>> correlation energy and potential are ignored! But “EX_GRR VX_GRR” alone,
>> means there is a kind of correlation energy and potential as a default for
>> usual mbj calculation. Did I realize
>>             correctly??
>>
>>             You answered the question about the use of the PBE instead of
>> LDA for the energy before:
>> http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg13395.html
>>
>>             And it is stated that how we must change case.in0 .
>>
>>             But there is no instruction for case.in0_grr. What should be
>> done for this issue?
>>
>>             (What kind of edition is correct for case.in0_grr? “EX_GRR
>> VX_GRR”? Or “ EX_GRR EC_NONE VX_GRR VC_NONE”?? I performed both of them for
>> one structure, and got very different result: different Gaps, different
>> total energies and different
>>             Fermi-energies!!! )
>>
>>             Please help me.
>>
>>             Sincerely
>>
>>             Shima M.Pourrad
>>
>>             PhD student of physics in condensed matter
>>
>>             Science and Research Branch
>>             Islamic Azad University
>>
>>
>>       _______________________________________________
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>>
>>
>>
>>
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