output the forces

My system contains a water droplet and a solid substrate. How can I get the forces between the water molecules (not include the forces between the solid atoms and the water molecules)

I think you probably can divide water into two groups.
And use compute group/group command to get the forces between water molecules.
If anyone has a better solution?

Dezhao Huang, Ph.D. student
University of Notre Dame
Department of Aerospace and Mechanical engineering

I think you probably can divide water into two groups.
And use compute group/group command to get the forces between water
molecules.
If anyone has a better solution?

​the request was not very well formulated, so it is not really possible to
provide a definite response.

typically, the most general approach to decompose​ forces into
contributions from different parts of the system, is to simulate a
trajectory with all interactions included. and then use the rerun command
to post-process that trajectory with only the interactions of interest
configured and everything else set to zero. notabene, for systems with
long-range coulomb via a kspace style, also partial charges need to be
overridden, or else the long-range terms will include contributions from
otherwise excluded atoms.

axel.