Hello:

I wonder whether it is possible to extend the command

sel @/serialNumber=18801 (as an example of a particular serial number)

to comprise a range of atoms. So as to cover, for example, an entire ligand, may be dioxygen, 18801-18802. And whether that could be extended to define a centroid.

it is implied that I have prepared a large system based on segname (charmm ff with namd), which is not dealt with by chimera.

thanks

francesco pietra

PS: I can follow the ligand by defining the centroid for a single atom of the ligand. This would be my last resource.