The attached example script calculates the overall momentum of atoms in a unit cell for the X, Y, and Z components of velocities. I needed this for another post in the community to make sure that there is a net-zero momentum after a Forcite MD run.

The .txt file has to be renamed to .pl

Please keep in mind that scripts come as they are without any entitlement to get further support for them and without any guarantee that it really does what it claims to do.