I asked the CCP4 experts this question a while back--maybe try searching the archive? There were some very helpful comments.
Jacob On Tue, Aug 2, 2011 at 1:24 PM, Young-Jin Cho <yj...@brandeis.edu> wrote: > Dear CCP4 experts, > > I would like to ask if there is a clear way to distinguish Na+ and HOH > molecules in the electron density map. The table I have suggests Na > to O distance lies between 2.35 and 2.45 that is very hard to discern > the difference of these two candidates. Na+ may have several > coordination though (5, 6). > > This started from if where the divalent metal locates can be > substituted by water or sodium. I would appreciate any valuable > suggestions. > > Best, > Young-Jin > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu *******************************************
