stress/atom pair

Hii all,

If for the compute stress/atom , keyword “KE” measures only the kinetic energy contribution to stress and “virial” calculates only the interaction contribution to stress. Then what is the use of “pair” keyword".

In short. what is the difference between command

compute all stress/atom NULL

compute all stress/atom NULL pair


from the documentation:

If no extra keywords are listed, all of the terms in this formula are included in the per-atom stress tensor. If any extra keywords are listed, only those terms are summed to compute the tensor. The virial keyword means include all terms except the kinetic energy ke.