[gmx-users] potential energy of a system

[Justin Lemkul]

On 3/29/17 8:43 AM, Mark Abraham wrote:
> Hi,
>
> The total potential energy has everything by definition, so I don't know
> what you're asking.
>
> Additivity of the components of the potential energy is an artefact of the
> construction of the model physics. While it is true that different physical
> phenomena underlie some of the components, the parameterization of the
> force field did not target meaningful decomposition of the potential
> energy. But you might be able to benefit from fortuitous cancellation
> effects when comparing such things.
>

Nitpick here: in CHARMM (and our polarizable model), we seek to get a variety of 
QM interaction energies explicitly correct (interactions with water, ions, other 
small molecules) so indeed there is some reliability in these metrics with 
CHARMM.  Of course, like all force fields, there is some inherent error 
cancellation but we do make an effort to get all of this kind of stuff right. 
Most other force fields, of course, do not, seeking instead to get overall 
properties correct, leaving the details to be debatable.  We try to get it all :)

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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