On Mon, Nov 24, 2008, hfox1.nd.edu wrote:
>
> We've recently become interested in performing periodic QM/MM calculations
> in Amber, but with a purely QM system.
No, Amber is no where close to being able to support this capability. I think
Ross' earlier explanation says it well:
> Unfortunately in Amber 9 [or 10!] one cannot do a pure QM periodic
> system. You can only do QM/MM with periodic boundaries and this has the
> restriction that the QM region dimension + cutoff must not extend beyond the
> box boundaries. I.e. it is designed for modelling say an active site in a
> protein that is then solvated.
Basically, there are only Coulomb interactions (and no exchange interactions)
computed between quantum regions in different unit cells. And, there is no
notion of k-space at all. We are simply attacking a very different problem
than the one you describe.
...dac
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" (in the *body* of the email)
to majordomo.scripps.edu
Received on Fri Dec 05 2008 - 16:42:18 PST
