[AMBER] Dihedral parameters for sp carbon in GAFF

From: Hai Long <spaceshiptoo.gmail.com>
Date: Wed, 29 Jun 2011 17:38:08 -0600

Dear All:

I'm trying to run simulations for molecules containing structures such as
using GAFF force field.
So I checked gaff force field for sp carbon parameters. However, I
found that all of the dihedral parameters for sp carbon such as cg
(Inner Sp carbons in conjugated systems) have zero PK value. For
X -cg-cg-X 1 0.000 180.000 2.000 for both
triple and single bonds

For the sp2-sp conjugate system, I don't think the zero PK is correct.
Are there any particular reasons to have this zero here or the zero is
just a placeholder and the parameter is still unknown?

Another question is: The definition of "ch" type is:" identical to
cg". So I don't understand why we need a "ch" type.

Thanks in advance!

Hai Long

AMBER mailing list
Received on Wed Jun 29 2011 - 17:00:03 PDT
Custom Search