[lammps-users] fix nvt/nve and fix momentum

Hi, Dear lammps-users

A quick question about two commands:

Does the command 'fix nvt/nve' not necessarily include function of zero the momentum of a group? Should I still use 'fix command' to keep momentum zero? If so, use 'fix momentum zero' before or after 'fix nvt/nve'? Thanks for any responding.

Regards,
Pengxiang

Normally, momemtum will be conserved using fix
nve or nvt by themselves (assuming it is for
a group of atoms with no external forces, i.e. all
the atoms). Otherwise you can add fix momentum.
The order doesn't really matter unless you think the
time integration will change the momentum dramatically.
Then use it after the integrator.

Steve