Re: [AMBER] E(QM), E(MM), and E(QM/MM) components of the potential energy in sander output

From: Andreas Goetz <>
Date: Fri, 22 Oct 2010 11:37:56 -0700

Dear Dmitry,

EPtot is the total potential energy which is the sum of all classical and quantum energy terms:
EPtot = E(QM) + E(MM) + E(QM/MM)

PM3ESCF (when using PM3) is the total SCF energy (heat of formation in the case of PM3 and other semiempirical methods) which includes the electrostatic components of E(QM/MM) (in periodic calculations this also includes interactions with the images).

The non-bonded (Lennard-Jones type) component of E(QM/MM) is included in VDWAALS.

All the best,

On Oct 22, 2010, at 5:27 AM, Dmitry Nilov wrote:

> Dear Amber community!
> I'm new in QM/MM calculations so it is hard to me to interpret the
> output of hybrid simulation.
> According to QM/MM concept, the hybrid potential is E = E(QM) + E(MM)
> + E(QM/MM).
> In sander output, there are EPtot and PM3ESCF (when using PM3)
> components, but I don't quite understand how they relate to E(QM),
> E(MM), and E(QM/MM).
> Cold you be so kind to help!
> --
> Dmitry Nilov,
> Lomonosov Moscow State University
> _______________________________________________
> AMBER mailing list

Dr. Andreas W. Goetz
San Diego Supercomputer Center
Tel  : +1-858-822-4771
Web  :
AMBER mailing list
Received on Fri Oct 22 2010 - 12:00:05 PDT
Custom Search