How to modify the F calculation method?

Using the DPD method in lammps, how to modify the F calculation method in the DPD method (define the interaction force between particles yourself), normally F is composed of dissipative force, random force and conservative force

You have to modify the source code of the dpd pair style and recompile. Please note, that there are already several “flavors” of dpd implemented in LAMMPS. Just check the manual.
Axel.