[Chimera-users] Intersurf

Hi everybody and happy New Year I'm using Intersurf to define the interface between two sub-units of a protein. Intersurf selects the atoms which appear to be far from the interface. Changing the prune distance from the default value of 30 to, say 10 or less has no effect on the atom selection. Is this right? Is there a way to select atoms that lie, say 5 Angstrom on either side of the interface. Thanks and best regards George