problem about bond in reax/c

Dear all,
I’m doing some researches with reax/c in LAMMPS. I want to know how to fix connectivity of bonds to avoid the reaction when I heat or balance the system . Could you give me some suggestions? Thanks.
Best regards,
Jie Wang

You can’t with ReaxFF, at least not in a simple way. The only way (which is only experimental) is to add harmonic bonds (bond_style harmonic) and assign strong force constants but this should be done carefully. Another method is to use shake or rattle, but again this has to be done carefully. In either case, you need to specifically define the bonds you’d like to fix.