Dear Ayesha,
Probably your structure within your selected QM region is not reasonable, for instance too distorted or there are very close contacts, which can lead to SCF failures. Try to equilibrate with MM first before switching to QM/MM. In addition, Amber17 has been released, you may want to upgrade.
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 Jun 3, 2017, at 7:58 AM, Ayesha Fatima <ayeshafatima.69.gmail.com> wrote:
>
> Dear all,
> I have a protein ligand system prepared using Amber12 forcefield. I want to
> run on the cluster that has amber14 installed on it. When I run the
> simulation, it gives me the error
>
> QMMM: ERROR!
> QMMM: Unable to achieve self consistency to the tolerances specified
> QMMM: No convergence in SCF after 1000 steps.
>
> is it because of difference in amber versions? I had previously run on
> cluster with amber12 where there was no error generated.
>
> thank you
> Ayesha Fatima
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Received on Sat Jun 03 2017 - 09:00:02 PDT
