[lammps-users] pressure when there is a rigid region in the system

Hi Steve,

This is related to a question Ly Le asked about a week ago, and you responded but I am not sure I understand.

I want to do some simulations in which part of the system is kept rigid, and part is mobile. I started with a simple
case in which I make rigid a portion ("wall") of an atomic system, and compared some thermo output for that "wall+mobile"
case compare with the "all mobile" case (run for 0 steps, 12Feb version). The results are understandable for T and energy,
but very odd for the pressure:

                            step temp pe etotal press pxx pyy pzz
all mobile 0 300 -5390.1874 -4933.2328 171.97493 -460.29472 422.94152 553.278
wall+mobile 0 279.3853 -5390.1874 -5195.3134 -22262.25 102897 4649.3093 -174333.06

If Lammps computes the pressure according to: