The size {HEAD ~ D} of the current path is {TAIL ~ 0.5 to 10 nm}, and typically 1 to 6 nm 
The size { HEAD ~ D } of the current path is { TAIL ~ 0.5 to 10 nm } , and typically 1 to 6 nm
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH