limit the atoms in one direction

Dear all,

I would like to set a system that the atoms’ velocity is random and only have z velocity. The atom is moved by a force I set which only change its z velocity. I tried to use “velocity all create 300.0 4928459 rot yes dist gaussian” But it will give the atoms x y velocity. Could you help me?


The easiest way to do it would be using another “velocity” command to zero the x and y components of velocity and after that using fix temp/rescale to get 300K.