Hi all, I've had an interesting question from an undergradute student, asking if there's any specific reference for the "18Å rule of thumb" in small molecule crystallography for dividing the volume of a unit cell by 18 for the approximate number of non-hydrogen atoms.
I'm afraid my google-fu has failed me, but I was curious as to whether there is a reference associated with the practice of if it's just one of those handy little pieces of advice for crystal screening. Thanks, Natalie Natalie J. Tatum http://about.me/tatum.nj PhD Researcher Pohl Group Durham University
