[lammps-users] mix available or make a new style?


I'm using cvff with lammps. I'd like to check the energy calculation against
Materials studio which also supports cvff.
I checked the manual. cvff uses a morse bond style and harmonic styles for
angle and dihedral terms. It also needs
the valence cross terms, like bondbond, bondangle,...

How can I use bond, angle and dihedral styles other than used for class2
style ,but still adding the crossterms?
e.g. a cosine angle_style plus the bondbond interaction? A hybrid style
seems not working in this case.