I’m trying to set up a constant-force pulling simulation but was a little confused on the difference between setting the mdp parameter pull_coord1_geometry to distance or direction. My understanding is that for distance, the pulling occurs along whichever axis is selected in pull_coord1_dim and for direction, it is pull_coord1_vec that is specified, but in the case of a constant-force pulling along only the z-direction, is there any difference between choosing pull_coord1_geometry = distance and setting pull_coord1_dim = N N Y as opposed to pull_coord1_geometry = direction and pull_coord1_vec = 0 0 1?