If you have the center coordinates and your cell has a good radial symmetry, i would just write a script, checking the distance of each water to the center and then skipping everything below the radius of your cell.
Cheers Martin _______________________________________________ gmx-users mailing list gmx-users@gromacs.org http://www.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to [EMAIL PROTECTED] Can't post? Read http://www.gromacs.org/mailing_lists/users.php