How to use TraPPE force field in LAMMPS ?

The united-atom force field TraPPE uses fixed bond lengths. How to fix bond lengths in LAMMPS? Is there any example file?
The command ‘bond_style zero’ cannot get correct results.

The united-atom force field TraPPE uses fixed bond lengths. How to fix bond
lengths in LAMMPS? Is there any example file?

rigid bonds can be realized in LAMMPS with fix shake or fix rattle.
however, for parallel efficiency reasons, there are limitations. e.g.
connected chains of rigid bonds are not possible. you'll find plenty
discussions on the topic in the LAMMPS mailing list archives.

please keep in mind that TraPPE is designed with monte carlo
simulations in mind, where these parallelization concerns do not
apply.

The command 'bond_style zero' cannot get correct results.

of course not. just read the documentation. it does *nothing*, so how
could this work at all?

axel.