[Octopus-users] Geometry optimisation
Robertson.Burgess at newcastle.edu.au
Fri Sep 24 01:48:01 WEST 2010
Sorry, perhaps I didn't explain my problem well enough.
My SCF cycles are converging. It just continues to converge SCF cycle after SCF cycle. The problem I have is it never reaches a minimisation iteration. i.e. the output file never comes up with a line like
+++++++++++++++++++++ MINIMIZATION ITER #: 1 ++++++++++++++++++++++
I got two such lines in my first geometry optimization run, then it seems to have gotten stuck after two. Now when I'm running it another time I still haven't gotten one, and it has converged 21 SCF cycles in a row.
>>> David Strubbe <dstrubbe at berkeley.edu> 21/09/10 4:53 PM >>>
If you can't get convergence, then you need to play with the Mixing and/or
Smearing. The lack of SCF convergence probably has nothing to do with
geometry optimization; if you start over for a gs calculation with the same
geometry you should have the same results (or lack thereof). It is useless
to specify so many ExtraStates unless they are all occupied to some
non-negligible degree. Also you may not need to go to ConvAbsEv = 1e-4. What
if you just use the default tolerance?
On Mon, Sep 20, 2010 at 8:42 PM, Robertson Burgess <
Robertson.Burgess at newcastle.edu.au> wrote:
> Dear octopus users.
> I'm performing a geometry optimization on a cluster containing 109 atoms. I
> ran the program once and it performed two minimization iterations before it
> just seemed to converge SCF cycle after SCF cycle without doing a
> minimization iteration.
> I then stopped that run, took the structure that it had already minimized
> to and put that as the new input structure. I then tried to run another
> geometry optimization run. So far during this run it has completed 17 SCF
> cycles, but still has not done one minimization iteration. Is there
> something I'm doing wrong, or something I can change to help the geometry
> optimization? Here is the contents of my inp file:
> LRConvAbsDens = 1e-3
> LinearSolverTol = 1e-5
> OutputHow= xcrysden
> SmearingFunction = fermi_dirac
> Smearing = 0.01
> TDEvolutionMethod= aetrs
> TDTimeStep =0.004
> Bob Burgess
> University of Newcastle
> Octopus-users mailing list
> Octopus-users at tddft.org
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