[lammps-users] COMPASS question

Are there other sources that explain the COMPASS force field in addition to the “SUN” papers? It’s a great paper on how the parameters were arrived at, but the mechanics of using them appears to require additional information. I’m working on a program to build a LAMMPS input files including the
COMPASS sections. I found a reference to a program (SYBYL) owned by Tripos/Certara that can build LAMMPS input files so it can be done. I have built the geometry part of the file and I am working on the force fields now. The atom types are fairly easy to identify from bonding and will be used to assign the potentials.

Also, is there a definition of an “improper?”

Thanks in advance,