Please direct your messages to the mainling list. This error is generated within the function ffinpt() called by pair style reax. It usually indicates that the ReaxFF parameter file is missing some entries. Since there is no ReaxFF Li-Si potential distributed with LAMMPS, you must have gotten the parameter file from somewhere else. You should ask the person who created the file why it is not working. There is a small chance that you might be able to avoid the error by using pair style reax/c, but I doubt it.
Aidan
I took a look at the files you sent. There seems to be a simple (but
inexplicable) error in ffield.reax. Nr of bonds line contains 16
instead of 3. If that was in the original publication, you should
notify the authors. With that correction, I was able to run for 100
steps with a small timestep using both reax and reax/c, getting
similar results from both, so maybe there are no other errors. You
should still assume the parameter file is wrong until you match the
published results. See attached tarball.
Aidan
haoran.tgz (21.1 KB)