reaxff interaction

Dear All:

I use reaxff forcefield and want to calculate the interaction between a molecule and the ZnO surface.

Is it possible to calculate the interaction between these two groups with lammps?

ReaxFF is not a pairwise additive force field, so it is not easily possible. LAMMPS features like compute group/group cannot work.
please note, that the interaction between the molecule and the surface depends on everything else indirectly, e.g. through charge equilibration or other many-body terms.