Electronic Convergence Problem!

Queries about input and output files, running specific calculations, etc.


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zhongchangwang
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Electronic Convergence Problem!

#1 Post by zhongchangwang » Sat Jan 20, 2007 9:46 am

Thanks for your attention.

I want to calculate a slab with external electric field. For small external electric field like 0.1 ev/A, I can achieve a converged total energy with the expense of more than 80 electonic steps. unfortunately, as soon as I increase the external field to 0.5 ev/A, the calculation shows no sign of convergence and its total energy is weird, like below,
RMM: 37 -0.352981988366E+06 0.80317E+03 -0.30545E+05 9483 0.148E+04 0.258E+02
RMM: 38 -0.341332444180E+06 0.11650E+05 -0.12314E+05 9272 0.148E+04 0.253E+02
RMM: 39 -0.328795963487E+06 0.12536E+05 -0.16718E+05 9301 0.147E+04 0.252E+02
RMM: 40 -0.353055503244E+06 -0.24260E+05 -0.28073E+05 9302 0.156E+04 0.256E+02

I did lots of trial calculations. as suggested by admin or others, but shows no improvement of electronic convergence. something imappropriate with my system?
Could anyone give me a suggestion on how to handle this problem? any advices are extremely welcome!

Thanks very much!
Last edited by zhongchangwang on Sat Jan 20, 2007 9:46 am, edited 1 time in total.

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Electronic Convergence Problem!

#2 Post by admin » Mon Jan 22, 2007 12:40 pm

did you switch on the dipole corrections?
Last edited by admin on Mon Jan 22, 2007 12:40 pm, edited 1 time in total.

zhongchangwang
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Electronic Convergence Problem!

#3 Post by zhongchangwang » Tue Jan 23, 2007 7:00 am

Thanks admin for response!
I added three commands to the normal INCAR, see the following:

ENCUT=350.000 #cutoff
EDIFF=1.0e-05
ISIF=0
ISMEAR= 0 #BZ integration method (for relaxation runs)
LWAVE=.FALSE.
LCHARG =.FALSE.
LBERRY = .FALSE.
ISYM= 0
ALGO = Fast
LREAL= Auto
EFIELD= 0.5
IDIPOL= 3
LDIPOL= .TRUE.
NELM= 200
LMAXMIX = 6

Since LDIPOL was set to True, I think maybe the dipole correction was switched on.
Maybe I am wrong, could you please check the INCAR for me. Thanks very much for your attention!
Last edited by zhongchangwang on Tue Jan 23, 2007 7:00 am, edited 1 time in total.

theseguys

Electronic Convergence Problem!

#4 Post by theseguys » Mon Jul 22, 2013 4:13 pm

[quote="admin"]did you switch on the dipole corrections?[/quote]
dear admin, I really want to if it is necessary to set ISYM=0 when set EFIELD=non-zero. this problem puzzle me for half a year, and I have search this problem for many times. thank you!
Last edited by theseguys on Mon Jul 22, 2013 4:13 pm, edited 1 time in total.

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