On Tue, 22 Aug 2017 10:47:49 +0200
"Traeg, Johannes" <johannes.traeg.fau.de> wrote:
> Hi AMBER users,
>
> I'm having trouble with a GAFF2 force field that I generated with
> ANTECHAMBER/LEAP. My molecule contains a triazole unit with an ethyl
> group connected to one of the carbon atoms of triazole. ANTECHAMBER
> correctly recognizes the atom types and, hence, my molecule contains
> the dihedral CC-CD-C3-C3 (CC and CD are identical in GAFF/GAFF2). The
> .prmtop file lists the following parameters for this dihedral:
>
> force constant = 0.0
> phase = 0.0
> periodicity = 3
>
> However, the GAFF2.dat file (Amber16) lists the following parameters
> for the dihedral CD-CC-C3-C3, which should be identical to
> CC-CD-C3-C3 (due to the equivalence of CC and CD):
>
> force constant = 0.157
> phase = 180.0
> periodicity = 3
>
> Can anyone help me out with this problem?
Have you run parmchk2 over the antechamber output and included the
frcmod generated in your leap session? BTW, GAFF atom types are all
lower case. That really matters.
Cheers,
Hannes.
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Received on Tue Aug 22 2017 - 02:30:02 PDT
