LAMMPS Temperature

Hello Ben,
please post to the list and not just to me. That way a record of this
conversation is kept in the archives and may help other people, and
you will get answers from other list participants as well.

Could you help explain to me the change in temperature. Why would
introducing say, 500ev PKA atom increase temperature by 50 degrees K or so?
I would think that the temperature would stay close to 300K since only one
atom has that energy. It seems to just shoot up to 350K or so right after I
introduce this PKA energy.

You can think of Temperature as a quantity proportional to the average
kinetic energy of particles in your system.
Whether the total kinetic energy is distributed evenly or unevenly (a
large fraction on the PKA) does not matter for the average