how to add a couple force to i,j particles?

forward communication sends the information to the ghosts; reverse communications sends the information assigned to a ghost to the original particle unit.

forward communication sends the information to the ghosts; reverse
communications sends the information assigned to a ghost to the original
particle unit.

​reverse communication _sums_ contributions from pairs, where one of the
atoms is a ghost and the other is a local atom to the local atoms
corresponding to the ghost atoms.
mind you, that these contributions are zero when pair_newton is off, and
that those ghost atom properties are not automatically reset to zero after
the reverse communication (for efficiency reasons).

axel.

axel.​