dear all I want to calculate the how many water molecule are their with in 3.5 A of a particular atom. could anyone help me in this regard E R Azhagiya singam -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20100820/7a9ed926/attachment.html>