[gmx-users] COMPASS force field revisited Bond Dihedral and Angle Dihedral cross terms

[Richard Broadbent]

Dear All,

I am considering conducting a simulation of a polymeric system in
gromacs. I would like to use the COMPASS forcefield as it has a complete
parameter set for my molecule.

I believe the majority of the implementation is simple (though long and
fiddly). However, it has Bond-Dihedral and Angle-Dihedral cross terms.
These terms are not listed in either Chapter 4 or 5 of the Manual. Which
leads me to believe that they are not implemented. However CMAP
dihedrals are not documented in chapters 4 & 5 and they are implemented
in the code. I therefore had a quick look in src/gmxlib/ifunc.c and
couldn't see those terms. However, my knowledge of the layout of the
source code is extremely limited so I could be looking in the wrong
place, and thought it best to ask.

Are Bond-Dihedral and Angle-Dihedral cross terms available in gromacs
4.5.5?


Thanks,

Richard