I am running a simulation with ReaxFF on ubuntu (windows). My model simulation is composed of a polymer-ion system including C/H/O/N/Li/S/F. I have run my simulation using ffield.reax.hns (C/H/O/N force field) from LAMMPS example. It works fine.
However, when I run my simulation with a ReaxFF which is not included in LAMMPS (C/O/H/F/Li/S force field) I get “NaN” for pressure. I thought there might be something wrong with my atom coordination. Everything sounds fine with no overlapping.
You have to “debug” your system and the force field parameters.
This can be done, for example, by trying to reproduce results from the publication describing the parameters.
Also you can set up small, trivial test systems with just a minimal number of elements and see if you can get the expected behavior and structures from it.
Build this gradually up to make it more complex with more elements and monitor carefully whether everything remains reasonable.
This is just standard procedure in research when you get unexpected results: you have to backtrack and check every step and every detail whether you did everything correctly until you can identify the step or detail where things go wrong. Then you have to think about whether and the error is expected and caused by a mistake in the input or a property of the settings and parameters you use.
Dear Developers and users,