            (6) upper z bound of region
         remainder
               no other parameters required
       
used with &quot;create temp&quot; command to initialize velocities of atoms
by default, the &quot;create temp&quot; command initializes the velocities of all atoms,
  this command limits the initialization to a group of atoms
this command is only in force for the next &quot;create temp&quot; command, any
  subsequent &quot;create temp&quot; command is applied to all atoms (unless the
  &quot;create