[gmx-users] CMAP in Gromacs Vs. CHARMM

[Andy Somogyi]

Hi, 

I'm trying to figure out the differences between Gromacs and CHARMM implementation of CMAP.

In Gromacs it seems to be defined as a 5 body term, whereas in CHARMM, its a 8 body term. 

I thought CMAP was a correction between a pair of dihedrals, 4 atoms define a dihedral, so I'm not sure how the .top format can specify this relationship using only 5 atoms.

Could anyone shed some light on converting between them. 

thanks