thank you for the suggestions. i will try them out.
thank you again
On Mon, Nov 24, 2014 at 2:27 PM, Andreas Goetz <agoetz.sdsc.edu> wrote:
> Dear Ayesha,
>
> You are trying to converge the SCF very tightly. Probably your electron
> density is well converged but not to the thresholds you requested. This
> might be the reason for failure. Try setting tight_p_conv=0 (this is
> default) and possibly scfconv=1.0e-8 which should be sufficient.
>
> I also noticed you are using a very large cutoff. Using cut=9.0 is usually
> sufficient.
>
> All the best,
> Andy
>
> --
> Dr. Andreas W. Goetz
> Assistant Project Scientist
> San Diego Supercomputer Center
> Tel : +1-858-822-4771
> Email: agoetz.sdsc.edu
> Web : www.awgoetz.de
>
> On Nov 23, 2014, at 10:10 PM, Ayesha Fatima wrote:
>
> > Dear all,
> > I am trying to run a qm/mm on a protein-ligand system. I have
> successfully
> > done classical MD without errors. As per information on the mailing list,
> > for qm/mm, i used a well equilibrated .rst file from the classical MM
> > method and was able to do further equilibration with qm/mm using the PM3
> > Hamiltonian. It is in the MD production phase.
> > I want to repeat the same with SCC-DFTB but unfortunately it keeps giving
> > errors in the equilibration phase such as
> >
> > QMMM SCC-DFTB: !!!! ============= WARNING ============= !!!!
> > QMMM SCC-DFTB: Convergence could not be achieved in this step.
> > QMMM SCC-DFTB: The calculation will continue, but energies and
> > QMMM SCC-DFTB: forces for this step will not be accurate.
> >
> > I have looked around on the mailing list and know its a common error. I
> > also tried using the PM3 equilibrated file and trying to further
> > equilibrate it with the SCC-DFTB. But the error still remains. I am
> > attaching my input file. I am sure someone has done it and resolved the
> > issue. Could they share their experience?
> > Thank you
> > Regards
> > Ayesha Fatima
> > PhD candidate UM
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Received on Sun Nov 23 2014 - 23:00:02 PST
