Thank you for your suggestion. I have been updated the version of lammps The version is LAMMPS (7 Dec 2015) now.
that is *still* an outdated version. there have been two (2!) stable
releases since then. but then again, the main issue is that you are
ignoring the most important advices from my e-mail.
I want to simulate the CO and H2 on nickel.
However, the CO cannot adsorb on the nickel based on the reaxff forcefiled which provide by the ref.( Tavazza, F.,Senftle, T. P.,Zou, C.,Becker, C. A.&van Duin, A. C. T. Molecular Dynamics Investigation of the Effects of Tip–Substrate Interactions during Nanoindentation. The Journal of Physical Chemistry C 119, 13580-13589 (2015).) May be this is not a good idea to merge two reaxff.
apparently, your attention is very selective. i already *explicitly*
stated, that what you are trying to do is a very, *very* bad idea.
there are no "maybe"s there. how much more drastic should i get?
However, I cannot find other reasonable forcefields to describe the interaction between NI and O.
you are looking for the interaction of Ni and CO and not Ni and O.
that is a very different thing. you seem to be thinking that
classical/empirical force fields can be employed similar to
pseudoptentials in plane-wave DFT. they cannot. as i already stated,
your approach is wrong at a very fundamental level.
Hence, I want merge the two exist reaxff about (Ni,C,H)(ref. Mueller, J. E.,van Duin, A. C. T.&Goddard, W. A. The Journal of Physical Chemistry C 114, 4939-4949 (2010).) And reaxff about (Ni O) (I have been test oxygen atom on the nickel.)
pair_style hybrid/overlay reax/c lmp_control reax/c lmp_control
pair_coeff * * reax/c 1 ffield.reax.nich C H Ni NULL
pair_coeff * * reax/c 2 ffield.reax.FC NULL NULL Ni O
fix 2 all qeq/reax 1 0.0 10.0 1e-6 reax/c
Now the error is "ERROR: No pair reax/c for fix qeq/reax (../fix_qeq_reax.cpp:165)"
i already explained what the constraints for mechanical coupling of
manybody force fields are. your setup violates that and is flat out
wrong as all Ni-Ni (and Ni-Ni-Ni and Ni-Ni-Ni-Ni) interactions are
computed twice, but others, e.g. O-C, Ni-O-C, Ni-C-O and many others
your main problem seems to be that you are confusing a syntactically
correct LAMMPS input with a meaningful LAMMPS input. you may be able
to get past syntax restrictions, but with your approach for this kind
of system you will *NEVER* get a meaningful simulation.
either you get *one* set of parameters that can correctly cover *all*
Ni, CO and H2 together at the intended conditions, or you'll have to
resolve to other, less empirical, methods.