[gmx-users] Wildcards and dihedral type 9

[Antila Hanne]

Dear experts,

I'm a bit confused about the use wildcards in the dihedral definitions
of .itp force field files. I'm under the impression that explicit
definition of a dihedral (e.g. OS-CT-CT-OS) is always used if
available and it overwrites any wildcards (for example X-CT-CT-X) that
might match that particular dihedral. However:

1. Does the explicit definition replace wildcard if they have
different periodicity. That is, are the expressions matched based on
atom types alone or atom types and periodicity?

2. Does the use of dihedral type 9, which enables summation of several
(type 1) dihedrals, have an effect on this?

 Thanks for the help!

 Hanne Antila
 Phd student
 Aalto University
 Finland