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NEB convergence problem

Posted: Thu Jul 03, 2008 5:33 am
by mff7d
I'm doing a simple transition state calculation and in my output file I get the below error. I went to look this up in the VASP manual, however, it indicated that there should be a variable 'trialstep' by which I should multiply my POTIM to get proper results. When searching through both the standard output file and OUTCAR I found no such variable. What do I do? What should I change my POTIM to? What caused this problem?



N E dE d eps ncg rms rms(c)
RMM: 1 -0.170723749625E+03 -0.17072E+03 -0.33973E-03 4609 0.122E-01 0.158E-02
RMM: 2 -0.170723841954E+03 -0.92329E-04 -0.11064E-04 2917 0.186E-02
20 F= -.68218749E+03 E0= -.68218117E+03 d E =-.492797E-02
BRION: g(F)= 0.119E-02 g(S)= 0.000E+00
BRIONS problems: POTIM should be increased
retain N= 1 mean eig= 9.29
eig: 9.290
bond charge predicted
N E dE d eps ncg rms rms(c)
RMM: 1 -0.170723884281E+03 -0.17072E+03 -0.57046E-04 4312 0.537E-02 0.734E-03
RMM: 2 -0.170723896102E+03 -0.11821E-04 -0.23401E-05 2196 0.943E-03
21 F= -.68219020E+03 E0= -.68218385E+03 d E =-.270717E-02
BRION: g(F)= 0.112E-02 g(S)= 0.000E+00
BRIONS problems: POTIM should be increased
retain N= 1 mean eig= 8.50
eig: 8.503
reached required accuracy - stopping structural energy minimisation
writing wavefunctions

NEB convergence problem

Posted: Thu Jul 03, 2008 7:33 am
by Haley
When you are not sure how large the optimal POTIM is, you can use the default value for the tag POTIM. In that case, the stdout will contain the messages you refered above.