Hello

I am trying to measure (from command line) the distance between

atom NH1 in residue 27, chain M

atom OG1 in residue 215, chain A

command

distance :27@NH1 :215@OG1

error: 6 atoms were selected.

The error message is correct because the system is a homotrimer.

My question: any way to specify the chains? Any of my attempts failed.

Thanks for advice (getting distances from the command line would be quicker that graphically as I have a large number of disnces to measure)