[gmx-users] md engine detection for different force field

[gromacs query]

Dear All,

How md engine in GROMACS (mdrun) detects which energy function to be used
as it varies for different force fields (FF). Does it detects automatically
from top file format, please correct me if wrong, or some other flag is to
be provided in mdp file? e.g. CHARMM FF  function and AMBER FF function has
different way of handling as CHARMM FF includes Urey-Bradley term extra.

Thanks