[Pw_forum] nstep parameter for geometry optimization
gryko at jsu.edu
Tue Dec 10 04:13:58 CET 2013
I am trying to optimize geometry of a FCC crystal containing 36 atoms.
The optimization runs fine, but pw.x stops after 3 bfgs steps with a
The maximum number of steps has been reached
End of BFGS Geometry Optimization
I increased the n step parameter to nstep=1000, but no change.
The total force is very small, Total force = 0.000178 (Ry/au),
and the largest force acting on atom is approx. 0.000029 (Ry/au).
Does this mean that forces are too small and optimization must stop
at this point?
Unfortunately, even with such small forces, a number of
vibrational frequencies calculated by the PHONON run is still negative.
Thank you very much,
More information about the users