Switch off the interaction between carbon-carbon

Hi, I have carbon in water system with CHARMM force field( 1-carbon, 2-Hydrogen, 3-Oxygen), I want to switch off the interaction (through the CHARMM ff) between carbon-carbon in that system, and replace the carbon-carbon interaction by a repulsive Lennard-Jones interaction. I have attempted to do this using the pair_style hybrid command in the following way.

pair_style hybrid lj/charmm/coul/long 8 10 lj/cut 3.550053

pair_coeff 2 2 lj/charmm/coul/long 0.046 0.4000135 0.046 0.4000135
pair_coeff 3 3 lj/charmm/coul/long 0.1521 3.150574 0.1521 3.150574
pair_coeff 1 2 lj/charmm/coul/long 0.057 1.975 0.057 1.975
pair_coeff 1 3 lj/charmm/coul/long 0.1032 3.35 0.1032 3.35
pair_coeff 1 1 lj/cut 0.07 3.550053

Is this the correct approach?

yes, something like that should work.

You can verify for yourself that things are working

as you expect by using the compute group/group

command where the 2 groups are each a single C atom,

and toggle between regular CHARMM and your lj/cut

in the input script to see if the forces change.