Set the environment variable MSI2LMP_LIBRARY or copy cvff.frc and cff9*.frc or any other *.frc files (which you have license to use) to this directory for use with msi2lmp.

Note that LAMMPS does not distribute Accelrys (or old BioSym) force field files, since they are proprietary. All the files in this directory that are part of the LAMMPS distribution are are openly available files that are in the public domain.