How to perform reaxFF simulation using several parameter files

Dear lammps users

Recently, I am struggling to perform some reactive MD simulations on a system consist of a few gas molecules and two graphene sheets. I have found two parameters files one for the gas molecules and, the other for the graphene sheets. But I need help with using the parameters file simultaneously. this is my input file:


dimension 3
boundary p p p
units real
atom_style charge
read_data data.graphene_inBox
pair_style reax/c NULL
pair_coeff * * ffield.reax C H O N
pair_coeff 1 1 ffield.carbonCondensedPhases C
neighbor 2.0 bin
neigh_modify every 10 delay 0 check no
timestep 0.5
fix 1 all nvt temp 100.0 300.0 500.0
fix 2 all qeq/reax 1 0.0 10.0 1.0e-6 reax/c
dump 1 all atom 30 dump.lammpstrj
run 10000

And I encounter this error:

Reading potential file ffield.reax with DATE: 2010-02-19
ERROR: Incorrect args for pair coefficients (src/USER-REAXC/pair_reaxc.cpp:301)
Last command: pair_coeff 1 1 ffield.carbonCondensedPhases C

Thanks, I appreciate it.
Hossein Hajiabadi

You cannot do this. You need one parameter file with parameters tuned for your entire system. This is how reaxff works. You cannot mix and match different files. This is not like quantum chemistry where you need to specify elements only. Reaxff parameters are very specific and thus not very transferable.