[Pw_forum] about neb

carlo sbraccia sbraccia at sissa.it
Thu Jun 3 10:04:29 CEST 2004

Dear Rongqin,
the meaning of Error= ***  is the following:
it represents the norm of the "neb"-force-vector acting on each image
divided by the number of degrees of freedom. With "neb"-force-vector I
mean both PES forces and spring forces (projected according to the neb
algorithm) which should be zero on the minimum energy path. 
error =  ***  is simply the largest Error on the images. This error is
used to check the convergence of the neb optimization (as is done in
standard ionic relaxations): when error < neb_thr convergence is
The total energies are given in eV, the errors in eV/Angstrom.
In the forthcoming version of PWscf (present CVS version) the output of
neb will be improved in order to be clearer than now (units will be
explicitly written).
carlo sbraccia

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