how to change nbrhood_cutoff in simulation using reax package

I don't know. I would talk to the 2 developers of the ReaxFF potentials
in LAMMPS. They are CCd on this message.


The near-neighbor cutoff distance is *not* part of the ReaxFF potential
specification. You won't find it in any of the published accounts of the
potential. Rather it is a parameter in the particular implementation of
ReaxFF developed by Metin Aktulga, which we call pair_style reax/c. The
other implementation of ReaxFF, pair_style reax, does not use the
near-neighbor cutoff.


As you mentioned, in the control file you just need to change the nbrhood_cutoff parameter to the value you want (it is given in A, a typical value is 4.5 or 5 A).

Could you get the problem with your ZnO_reax/c system resolved? I did not have time to look into it so far.