[gmx-users] Multiplicity of a dihedral

[Mark Abraham]

On Wed, Jan 30, 2013 at 2:17 PM, Jong Wha Lee <jongwha12 at postech.ac.kr>wrote:

> Hello,
>
>
>
> How is the multiplicity of a dihedral determined? I know that it is related
> to the number of minima, but then how could we determine the number of
> minima? Is it with chemical intuition or with QM calculations?
>

Usually with intuition and whatever makes the model fit the
parameterization observables.

My molecule has several rings, which makes it not possible to calculate
> energetics when changing dihedral angles(the ring breaks). In this case,
> can
> I isolate just the four atoms (and hydrogens) and calculate energetics?
>

What are you trying to observe?

Mark