Dear BB
I have (again) realised how limited by understanding of our subject is. In Nature’s online site http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14110.html?WT.ec_id=NATURE-20150129 there is a paper describing an X-ray structure determined with sub-atomic data (nice!). The figures show density for H+ as well as H-. In my simple way I had assumed that any X-ray scattering from the nucleus was negligible, and that the electrons are responsible for this. I would expect a proton (i.e. H+) alone to be invisible to X-rays, and certainly not to look similar to a hydride (with two electrons in (electron density) maps. What have I missed? Could someone please explain, or point me to a suitable reference? Best wishes, Peter (please use peter.mo...@le.ac.uk to reply directly) http://www2.le.ac.uk/departments/biochemistry/staff/moody
