[AMBER] Hybrid QM/MM Convergence

From: Ahmed Ayoub <atayoub.ualberta.ca>
Date: Sat, 2 Nov 2013 22:25:51 -0600

Dear Amber experts,

I'm doing a hybrid QM/MM minimization using Gaussian 09 as an external QM
agent. When I specify the number of minimization steps in the CTRL
namelist, I sometimes notice a bizarre behaviour. The minimizer keeps
minimizing the SCF energy and at one point of time, the SCF energy rises up
again, sometimes tremendously, and again the minimzer restarts minimizing.
This keeps going till the max number of cycles is reached which could yield
an unminimized structure. This is kind of not what I want. I want basically
to reach convergence on the energy of the QM region. Is there any way to
avoid this behavior, or to specify a certain gradient for convergence
instead of using the maximum cycle approach?
Any help would be appreciated.

AMBER mailing list
Received on Sat Nov 02 2013 - 21:30:02 PDT
Custom Search