Correction - 2.4 on the HOH-Na distance. Should have read the book, I guess.
-----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Bernhard Rupp Sent: Monday, February 15, 2010 12:42 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Distinguishing Between Na+ and H2O HOH-Na distance about 2.1 A. Marjorie Harding's web page has a distance/geometry listing and derived table is in my appendix (I mean the one of the book..) http://tanna.bch.ed.ac.uk/index.html http://eduliss.bch.ed.ac.uk/MESPEUS/ BR -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Jacob Keller Sent: Monday, February 15, 2010 12:26 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Distinguishing Between Na+ and H2O Dear Crystallographers, I am looking at a 1.0 Angstrom structure which contains many waters, but I am wondering whether some of them might really be sodium ions. Is there any straightforward way to distinguish between these two, and if so, what is the software which implements this? Although the electron density difference between sodium and water should be very small, perhaps the binding geometry would provide a clearer distinction? Has anybody encountered this question before? Regards, Jacob Keller ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program Dallos Laboratory F. Searle 1-240 2240 Campus Drive Evanston IL 60208 lab: 847.491.2438 cel: 773.608.9185 email: j-kell...@northwestern.edu *******************************************
