A lot of intersting region-related features have appeared recently in
lammps (region functions for variables, compute temp/region).
In the same spirit, would it be possible to add a region keyword to
the velocity create command, enabling to create an initial temperature
in a given region with zero linear and angular momentum?
A current trick is to create a temporary group of the atoms being in a
given region at a given time using the set command, and then to apply
the velocity create command to this group, but it would be nicer if
one could do it directly through the velocity command only.