ionic convergence criterion

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rgc · #1 Post by **rgc** » Fri Mar 14, 2008 2:38 pm

Hi,

What is the ionic convergence criterion when ISIF=3 (cell relaxation)?

I guess that, if EDIFFG>0, VASP checks whether the difference between two consecutive energies is less than EDIFFG.

But what is the behaviour when ISIF=3 and EDIFFG<0? Negative EDIFFG means that ionic forces are checked to be less than |EDIFFG|, but when does the cell relaxation stop???

Thanks!

#2 Post by **admin** » Fri Mar 14, 2008 4:06 pm

the criterion then is that the maximum force component (on the atoms) and the maximum stress tensor component (on the cell) both have to be less than EDIFFG