Dear Hannes,
If your input structure is correct:
i.e. no hydrogen is missing
the total charge is correct
the bumps are removed
you might try a more robust code.
Let's talk about Gaussian vs Gaussian as an example:
i.e. Gaussian 03 versus Gaussian 09
there is an important speed and SCF convergence gap between g03 and g09
this is why we always propose the latest version of Gaussian at
R.E.D. Server Development
http://q4md-forcefieldtools.org/REDServer-Development/
http://q4md-forcefieldtools.org/REDServer-Development/news.php
more generally you could try to get a bunch of 50 molecules and run
the latest version of Gaussian (vs sqm). My feeling is that there is
no comparison; and I do not talk about the gradient value & the fact
that sqm is a semi-empirical code...
regards, Francois
> I can't get the attached structure (sqm.in) converged. What happens is
> that the wave function won't converge somewhere along geometry
> optimisation, at some arbitrary step (not the first step) depending on
> name list parameters.
>
> I have no particular interest in this one. The problem just came up in
> a larger test set. The structure is ZINC03814828. Same result with
> ZINC03814832 which is almost the same.
>
> The current name list is an outcome of playing around with various
> parameters but without luck. What I wonder is if this could still be
> made to converge or if there is a set of known structures which just
> cannot be converged? If I replace the carboxy-ethyl group with propyl
> the structure converges at scfconv=1.0D-9.
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Received on Thu May 08 2014 - 04:30:05 PDT
