[Wien] convergence problem :: runsp_c_lapw

Peter Blaha pblaha at theochem.tuwien.ac.at
Fri Apr 25 10:06:03 CEST 2014


Looking on your case.scf file it is rather clear that NOTHING is 
correct. I'll illustrate some of my "analysis" for pedagogical reasons, 
which is hopefully helpful also for others. One should really try to 
"READ AND UNDERSTAND" every single number in this scf file and CHECK THE 
NUMBERS IF THEY ARE PLAUSIBLE.

I can see that you have 12 Sm atoms in your structure (and many B) and:

          ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Sm1
:e__0001: OVERALL ENERGY PARAMETER IS    0.2490
           OVERALL BASIS SET ON ATOM IS LAPW
:E0_0001: E( 0)=    0.2490
              APW+lo
:E0_0001: E( 0)=   -2.4678   E(BOTTOM)=   -2.861   E(TOP)=   -2.074  4 
5   170
              LOCAL ORBITAL
:E1_0001: E( 1)=   -0.9351   E(BOTTOM)=   -1.621   E(TOP)=   -0.249  3 
4   166
              APW+lo
:E1_0001: E( 1)=    0.2490
              LOCAL ORBITAL
:E3_0001: E( 3)=    0.5504   E(BOTTOM)=    0.402   E(TOP)=    0.698  0 
1   129
              APW+lo
:E2_0001: E( 2)=    0.2490   E(BOTTOM)=    0.080   E(TOP)= -200.000  2 
-1    97
              APW+lo


This tells me that you should find 12 Sm-s eigenvalues around -2.5 and 
12*3=36 Sm-p eigenvalues around -0.9.
The eigenvalue list contains those eigenvalues, but in addition there 
are 11 eigenvalues around -0.6 ????
EIG00001:      -2.4155326   -2.4155314   -2.3843317   -2.3843304 
-2.3748427
:EIG00006:      -2.3748415   -2.3568118   -2.3564927   -2.3147676 
-2.3147673
:EIG00011:      -2.3078123   -2.3078121   -0.9883348   -0.9883193 
-0.9555305
:EIG00016:      -0.9555160   -0.9418705   -0.9418570   -0.9325269 
-0.9289614
:EIG00021:      -0.9289614   -0.9289544   -0.9289544   -0.9212251 
-0.8957374
:EIG00026:      -0.8955851   -0.8950323   -0.8950323   -0.8950244 
-0.8950244
:EIG00031:      -0.8880392   -0.8880392   -0.8880351   -0.8880351 
-0.8808041
:EIG00036:      -0.8805569   -0.8675999   -0.8675999   -0.8660532 
-0.8660532
:EIG00041:      -0.8348295   -0.8348295   -0.8348283   -0.8348283 
-0.8270829
:EIG00046:      -0.8270829   -0.8270757   -0.8270757   -0.6746033 
-0.6745923

:EIG00051:      -0.6567444   -0.6566515   -0.6452657   -0.6423593 
-0.6375798
:EIG00056:      -0.6304925   -0.6218711   -0.6121139   -0.6048921 
-0.2962034
:EIG00061:      -0.2957519   -0.2755786   -0.2622561   -0.2468627 
-0.2260104

 From where should they be ?  B states are not at this energy and 11 
states are immediately suspicious ???

These must be "wrong" (ghostband) states.
PS: This "counting" works of course only for the deep lying semicore 
states. You cannot do the same thing for the "real valence" states 
(closer to EF)
---------------

Also the analysis of scf2 shows:
:POS001: ATOM   -1 POSITION = 0.00000 0.00000 0.15275  MULTIPLICITY = 2 
  ZZ= 62.000  Sm1

        LMMAX 10
        LM=   0 0  1 0  2 0  3 0  4 0  4 4  5 0  5 4  6 0  6 4

:CHA001: TOTAL VALENCE CHARGE INSIDE SPHERE   1 =     7.325388
:PCS001: PARTIAL CHARGES SPHERE =  1 
S,P,D,F,PZ,PXY,,D-Z2,D-XY,D-X2Y2,D-XZ,YZ
:QTL001: 0.9850 2.6885 0.0999 3.5516 0.8947 1.7937 0.0000 0.0164 0.0336 
0.0105 0.0394 0.0000
         Q-s-low E-s-low   Q-p-low E-p-low   Q-d-low E-d-low   Q-f-low 
E-f-low
:EPL001:  0.9645 -2.4142    2.6273 -0.9544    0.0006 -0.9415    0.0003 
-0.8634
           ^^^^^^^^^^^^^^    ^^^^^^^^^^^^^^
So the Sm s and p states are at the expected energies and if you check 
all other atoms, you do not find any large charge around -0.6

----------------------
In addition in the scf file I find:

:FER  : F E R M I - ENERGY(TETRAH.M.)=   0.3587774860
:NOE  : NUMBER OF ELECTRONS          = 390.000
:CHA  : TOTAL VALENCE CHARGE INSIDE UNIT CELL =     193.022103

???  this :CHA should be exactly 390 / 2 = 195. ???

and therefore
:NEC01: NUCLEAR AND ELECTRONIC CHARGE   1074.00000  1070.35728
So you are "missing" 3.6 electrons.
-----------------------

In your scf file I can find the second EF

:FER  : F E R M I - ENERGY(TETRAH.M.)=  -0.7665217348

but then:
:NOE  : NUMBER OF ELECTRONS          =  90.000

Why 90 ???  it should be again 390.

This comes from case.in2eece, which is produced automatically from 
case.in2c.  It seems that there NE is for some reason too far on the 
left side and thus the script cuts away the "3" of 390.

-----------------------

In essence:
Start over in new directories with your struct file, but with a new 
initialization.

Try to run:

runsp_c_lapw
runsp_c_lapw -so
runsp_c_lapw -eece

runsp_c_lapw -eece -so

The difference between the last two calculations should be "minor".

Also using -orb instead of -eece should give MINOR differences in 
partial charges, eigenvalues,....

------------------------

Always use the LAST wien2k version, in particular do NOT mix scripts 
from different versions. runsp_c and runeece are VERY different and they 
have been bug fixed in 13.1 and would not work in 12.1
The "update" section of www.wien2k.at has even a note for 13.1:
   runeece_lapw (bug-fix for runsp_c); runsp_c_lapw (fix for -eece);

In my version I updated runsp_c and runeece further because of the 
in1orig switch (so don't use them).

PS: Before doing the surface, have you done the bulk ???
Did it work with runsp_c -so -eece ???



On 04/24/2014 09:17 PM, Peter Blaha wrote:
> The reason for your problems has nothing to do with "mixing".
>
> Your :DIS s already quite small, but how can :FER change from
> one iteration to the next  by 1 Ry ???
>
> Most likely there must be other reasons like some ghostbands appear,
> the fermi-energy deterination did not work out correctly, ....
> states felt below EMIN, the number of electrons is ne. sum of nuclear
> charges, ...
>
> Check :NEC01    Was it (almost) the same in all iterations ?
> Check :ENE   any warnings ... ???
>
> Look and "count" your states in the scf file, when your EF=-0.7 Ry
> and compare it with an iteration where EF is "normal".
>
> In order to do this, you should "understand" your low lying states
> (can be found from the E-parameters in the scf-file and the multiplicity
> of the corresponding atom. As  short example: Suppose you find for your
> first
> atom (a Ti) a low E-s parameter near -4.0 Ry and MULT=4 for the first
> atom, so you
> should find 4 eigenvalues around -4Ry (eg. the Ti 3s). Similarly, Ti
> should also
> 3p semicore states, eg. near -2.5 Ry, thus you should find 12
> eigenvalues around
> that energy. ....
>
> Hope this helps, otherwise I need 2 iterations of the scf file where
> those EF changes happen.
>
> PS: If you see such problems it could mean that you should start over,
> since such a density
> will NEVER converge.
>
> Am 24.04.2014 12:25, schrieb Martin Gmitra:
>> Dear Wien2k users,
>>
>> I am doing calculations of a hexaboride films invoking: runsp_c_lapw
>> -so -eece
>> My problem is two fold:
>>
>> (i) SCF calculations successfully converged for thin films (9 atomic
>> units) and bulk systems. I do have a problem to converge a thicker
>> film (11 atomic units) even TEMP
>> broadening of 0.02 is used. The observations after 800 iterations are
>> following:
>>
>> (1) fermi energy is jumping (roughly) between two values
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=   0.3682855520
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=   0.3682855520
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=  -0.7779431003
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=  -0.7779431003
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=   0.3683943150
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=   0.3683943150
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=  -0.7767634505
>> :FER  : F E R M I - ENERGY(FERMI-SM.)=  -0.7767634505
>>
>> (2) charge distance non uniformly oscillates between 0.1 and 0.001
>> :DIS  :  CHARGE DISTANCE       ( 1.1067771 for atom    4 spin 1)
>> 0.1064425
>> :DIS  :  CHARGE DISTANCE       ( 0.0059078 for atom    6 spin 1)
>> 0.0013328
>> :DIS  :  CHARGE DISTANCE       ( 0.0092322 for atom    6 spin 1)
>> 0.0015769
>> :DIS  :  CHARGE DISTANCE       ( 0.0092664 for atom    6 spin 1)
>> 0.0015106
>> :DIS  :  CHARGE DISTANCE       ( 0.5478509 for atom    4 spin 1)
>> 0.0466613
>> :DIS  :  CHARGE DISTANCE       ( 0.0078766 for atom    6 spin 1)
>> 0.0014700
>> :DIS  :  CHARGE DISTANCE       ( 0.9814094 for atom    4 spin 1)
>> 0.0939173
>> :DIS  :  CHARGE DISTANCE       ( 0.0070829 for atom    6 spin 1)
>> 0.0015672
>> :DIS  :  CHARGE DISTANCE       ( 0.0411319 for atom    4 spin 2)
>> 0.0053433
>> :DIS  :  CHARGE DISTANCE       ( 0.0072009 for atom    6 spin 1)
>> 0.0014308
>> :DIS  :  CHARGE DISTANCE       ( 0.1357701 for atom    4 spin 2)
>> 0.0150618
>>
>> (3) magnetic moments are zero within spheres whereas there is
>> :MMTOT: SPIN MAGNETIC MOMENT IN CELL   =    -0.00010
>> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL =   -0.00003
>>
>> (4) my case.inm
>> BROYD  0.0   YES  (BROYD/PRATT, extra charge (+1 for additional e), norm)
>> 0.005           mixing FACTOR for BROYD/PRATT scheme
>> 1.00  1.00      PW and CLM-scaling factors
>> 9999  8         idum, HISTORY
>>
>> :MIX  :   MSEC3  REGULARIZATION: 2.50E-04  GREED: 0.005  Newton 1.000
>> with PRATT after 100 iterations
>> MIX  :   PRATT  REGULARIZATION: 2.50E-04  GREED: 0.005
>>
>> Do you have any hints how to converge the calculations?
>>
>> (ii) I am running the calculations with version 12.1. The runsp_c_lapw
>> script has been updated (debugged) in version 13.1 but SCF diverges in
>> my cases (thin and thicker films).
>>
>> Does anybody experience similar problem?
>>
>> Best regards,
>> Martin Gmitra
>> Uni Regensburg
>>
>>
>>
>>
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>> SEARCH the MAILING-LIST at:
>> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>>
>

-- 

                                       P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
Email: blaha at theochem.tuwien.ac.at    WWW: 
http://info.tuwien.ac.at/theochem/
--------------------------------------------------------------------------


More information about the Wien mailing list