[gmx-users] Dummy atom in OPLS acetonitrile

[Thompson, Matthew White]

According to virtualchemistry.org<http://virtualchemistry.org/>, OPLS uses a dummy atom ML in its acetonitrile molecule The oplsaa.ff/ files that ship with gromacs don't include a ML atomtype and the original parameterization (10.1002/jcc.1092) appears to also not include it.

See http://virtualchemistry.org/molecule.php?filename=acetonitrile.zmat

Does anybody know when this dummy atom was added? I know there are other compatible models out there but I am looking for discussion of why it was added.

Matt