[Wien] convergence problem :: runsp_c_lapw

[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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20140424/cd82deef/attachment.htm>