[Wien] SCF convergence velocity

Torsten Andersen thor at physik.uni-kl.de
Tue Mar 23 07:50:07 CET 2004


Dear Daniel Kmiec,

I have also done some calculations on Fe/W systems, and see the same 
tendency. However, they usually converge after a few hundred iterations. 
I do not really know any big "tricks", but I use a mixer factor of 
0,15-0,25, usually, for charge convergence, in order not to get 
"uniform" convergence. To me, it looks like W is causing the problem.

Best regards,
Torsten Andersen.

Daniel Kmiec wrote:
> Dear Wien2k users,
> 
> First of all I want to thank you for all previous answers to my questions.
> Today I would like to ask about velocity of scf cycles. I'm calculating
> 88 atoms big system (Fe on W) and after something like 150 iterations,
> the charge convergence parameter equals to ~0.05 and it converges very 
> slowly.
> I attached(I hope it is allowed) my struct file and a plot of charge 
> convergence versus number of iteration. One can see that during ca 70 
> iterations
> starting from 60 till 130 the parameter stays almost constant.
> 
> I' doing spin polirized calculations, the RMT radius I've chosen is 2.45 
> , I also reduced mixer factor to 0.01.
> 
> Can you advice me how may I enhance the velocity of the scf cycles, 
> maybe by adjusting some parameters, which I leave with defaults values?
> 
> Best Regards
> Daniel Kmiec
> 
> 
> ------------------------------------------------------------------------
> 
> FeW_110_24_10_2003_vacancy                                                     
> P   LATTICE,NONEQUIV.ATOMS: 2347_Pmmm                                          
> MODE OF CALC=RELA unit=ang                                                     
>  18.084686 25.575564 45.353445 90.000000 90.000000 90.000000                   
> ATOM  -1: X=0.00000000 Y=0.00000000 Z=0.00000000
>           MULT= 1          ISPLIT= 8
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM  -2: X=0.16666667 Y=0.16666667 Z=0.00000000
>           MULT= 4          ISPLIT= 8
>       -2: X=0.83333333 Y=0.83333333 Z=0.00000000
>       -2: X=0.83333333 Y=0.16666667 Z=0.00000000
>       -2: X=0.16666667 Y=0.83333333 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM  -3: X=0.33333333 Y=0.00000000 Z=0.00000000
>           MULT= 2          ISPLIT= 8
>       -3: X=0.66666667 Y=0.00000000 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      0.0000000 1.0000000 0.0000000
>                     -1.0000000 0.0000000 0.0000000
> ATOM  -4: X=0.50000000 Y=0.16666667 Z=0.00000000
>           MULT= 2          ISPLIT= 8
>       -4: X=0.50000000 Y=0.83333333 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
> ATOM  -5: X=0.00000000 Y=0.33333333 Z=0.00000000
>           MULT= 2          ISPLIT= 8
>       -5: X=0.00000000 Y=0.66666667 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
> ATOM  -6: X=0.33333333 Y=0.33333333 Z=0.00000000
>           MULT= 4          ISPLIT= 8
>       -6: X=0.66666667 Y=0.66666667 Z=0.00000000
>       -6: X=0.66666667 Y=0.33333333 Z=0.00000000
>       -6: X=0.33333333 Y=0.66666667 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM  -7: X=0.50000000 Y=0.50000000 Z=0.00000000
>           MULT= 1          ISPLIT= 8
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM  -8: X=0.16666667 Y=0.50000000 Z=0.00000000
>           MULT= 2          ISPLIT= 8
>       -8: X=0.83333333 Y=0.50000000 Z=0.00000000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      0.0000000 1.0000000 0.0000000
>                     -1.0000000 0.0000000 0.0000000
> ATOM  -9: X=0.16666667 Y=0.00000000 Z=0.09400000
>           MULT= 4          ISPLIT= 8
>       -9: X=0.83333333 Y=0.00000000 Z=0.90600000
>       -9: X=0.16666667 Y=0.00000000 Z=0.90600000
>       -9: X=0.83333333 Y=0.00000000 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
> ATOM -10: X=0.33333333 Y=0.16666667 Z=0.09400000
>           MULT= 8          ISPLIT= 8
>      -10: X=0.66666667 Y=0.83333333 Z=0.90600000
>      -10: X=0.33333333 Y=0.16666667 Z=0.90600000
>      -10: X=0.66666667 Y=0.83333333 Z=0.09400000
>      -10: X=0.66666667 Y=0.16666667 Z=0.09400000
>      -10: X=0.33333333 Y=0.83333333 Z=0.90600000
>      -10: X=0.66666667 Y=0.16666667 Z=0.90600000
>      -10: X=0.33333333 Y=0.83333333 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -11: X=0.50000000 Y=0.00000000 Z=0.09400000
>           MULT= 2          ISPLIT= 8
>      -11: X=0.50000000 Y=0.00000000 Z=0.90600000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -12: X=0.00000000 Y=0.16666667 Z=0.09400000
>           MULT= 4          ISPLIT= 8
>      -12: X=0.00000000 Y=0.83333333 Z=0.90600000
>      -12: X=0.00000000 Y=0.16666667 Z=0.90600000
>      -12: X=0.00000000 Y=0.83333333 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
> ATOM -13: X=0.16666667 Y=0.33333333 Z=0.09400000
>           MULT= 8          ISPLIT= 8
>      -13: X=0.83333333 Y=0.66666667 Z=0.90600000
>      -13: X=0.16666667 Y=0.33333333 Z=0.90600000
>      -13: X=0.83333333 Y=0.66666667 Z=0.09400000
>      -13: X=0.83333333 Y=0.33333333 Z=0.09400000
>      -13: X=0.16666667 Y=0.66666667 Z=0.90600000
>      -13: X=0.83333333 Y=0.33333333 Z=0.90600000
>      -13: X=0.16666667 Y=0.66666667 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -14: X=0.50000000 Y=0.33333333 Z=0.09400000
>           MULT= 4          ISPLIT= 8
>      -14: X=0.50000000 Y=0.66666667 Z=0.90600000
>      -14: X=0.50000000 Y=0.33333333 Z=0.90600000
>      -14: X=0.50000000 Y=0.66666667 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
> ATOM -15: X=0.00000000 Y=0.50000000 Z=0.09400000
>           MULT= 2          ISPLIT= 8
>      -15: X=0.00000000 Y=0.50000000 Z=0.90600000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -16: X=0.33333333 Y=0.50000000 Z=0.09400000
>           MULT= 4          ISPLIT= 8
>      -16: X=0.66666667 Y=0.50000000 Z=0.90600000
>      -16: X=0.33333333 Y=0.50000000 Z=0.90600000
>      -16: X=0.66666667 Y=0.50000000 Z=0.09400000
> W          NPT=  781  R0=0.00000500 RMT=    2.4500   Z: 74.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
> ATOM -17: X=0.16666667 Y=0.16666667 Z=0.18800000
>           MULT= 8          ISPLIT= 8
>      -17: X=0.83333333 Y=0.83333333 Z=0.81200000
>      -17: X=0.16666667 Y=0.16666667 Z=0.81200000
>      -17: X=0.83333333 Y=0.83333333 Z=0.18800000
>      -17: X=0.83333333 Y=0.16666667 Z=0.18800000
>      -17: X=0.16666667 Y=0.83333333 Z=0.81200000
>      -17: X=0.83333333 Y=0.16666667 Z=0.81200000
>      -17: X=0.16666667 Y=0.83333333 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -18: X=0.33333333 Y=0.00000000 Z=0.18800000
>           MULT= 4          ISPLIT= 8
>      -18: X=0.66666667 Y=0.00000000 Z=0.81200000
>      -18: X=0.33333333 Y=0.00000000 Z=0.81200000
>      -18: X=0.66666667 Y=0.00000000 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
> ATOM -19: X=0.50000000 Y=0.16666667 Z=0.18800000
>           MULT= 4          ISPLIT= 8
>      -19: X=0.50000000 Y=0.83333333 Z=0.81200000
>      -19: X=0.50000000 Y=0.16666667 Z=0.81200000
>      -19: X=0.50000000 Y=0.83333333 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
> ATOM -20: X=0.00000000 Y=0.33333333 Z=0.18800000
>           MULT= 4          ISPLIT= 8
>      -20: X=0.00000000 Y=0.66666667 Z=0.81200000
>      -20: X=0.00000000 Y=0.33333333 Z=0.81200000
>      -20: X=0.00000000 Y=0.66666667 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
> ATOM -21: X=0.33333333 Y=0.33333333 Z=0.18800000
>           MULT= 8          ISPLIT= 8
>      -21: X=0.66666667 Y=0.66666667 Z=0.81200000
>      -21: X=0.33333333 Y=0.33333333 Z=0.81200000
>      -21: X=0.66666667 Y=0.66666667 Z=0.18800000
>      -21: X=0.66666667 Y=0.33333333 Z=0.18800000
>      -21: X=0.33333333 Y=0.66666667 Z=0.81200000
>      -21: X=0.66666667 Y=0.33333333 Z=0.81200000
>      -21: X=0.33333333 Y=0.66666667 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -22: X=0.50000000 Y=0.50000000 Z=0.18800000
>           MULT= 2          ISPLIT= 8
>      -22: X=0.50000000 Y=0.50000000 Z=0.81200000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM -23: X=0.16666667 Y=0.50000000 Z=0.18800000
>           MULT= 4          ISPLIT= 8
>      -23: X=0.83333333 Y=0.50000000 Z=0.81200000
>      -23: X=0.16666667 Y=0.50000000 Z=0.81200000
>      -23: X=0.83333333 Y=0.50000000 Z=0.18800000
> Fe         NPT=  781  R0=0.00005000 RMT=    2.4500   Z: 26.0                   
> LOCAL ROT MATRIX:    0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>                      1.0000000 0.0000000 0.0000000
>    8      NUMBER OF SYMMETRY OPERATIONS
> -1 0 0 0.0000000
>  0-1 0 0.0000000
>  0 0-1 0.0000000
>        1
> -1 0 0 0.0000000
>  0-1 0 0.0000000
>  0 0 1 0.0000000
>        2
> -1 0 0 0.0000000
>  0 1 0 0.0000000
>  0 0-1 0.0000000
>        3
> -1 0 0 0.0000000
>  0 1 0 0.0000000
>  0 0 1 0.0000000
>        4
>  1 0 0 0.0000000
>  0-1 0 0.0000000
>  0 0-1 0.0000000
>        5
>  1 0 0 0.0000000
>  0-1 0 0.0000000
>  0 0 1 0.0000000
>        6
>  1 0 0 0.0000000
>  0 1 0 0.0000000
>  0 0-1 0.0000000
>        7
>  1 0 0 0.0000000
>  0 1 0 0.0000000
>  0 0 1 0.0000000
>        8
> 
> 
> ------------------------------------------------------------------------
> 

-- 
Dr. Torsten Andersen                     TA-web: http://deep.at/myspace/
AG Hübner, Department of Physics, Kaiserslautern University, and
Condensed Matter Theory Group, Department of Physics, Uppsala University
Web: http://www.fysik4.fysik.uu.se/         http://www.physik.uni-kl.de/ 





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