I am not sure if you gave your wave length but it is always worth doing an anomalous map, and looking at relativr peak heights for your known S positions and the putative sulphate or phosphate. There are small differences in the expected f" at most wavelengths.
Chemical arguments are doubtless better of Course! Eleanor On 1 August 2018 at 16:54, armin.wag...@diamond.ac.uk < armin.wag...@diamond.ac.uk> wrote: > Dear David, > > The long-wavelength beamline I23 at Diamond (http://www.diamond.ac.uk/ > Instruments/Mx/I23.html) can go all way down to the phosphorous edge. > While data quality will be obviously compromised by absorption effects (we > are working on this), for a reasonably well diffracting crystal like yours > we should be able to get anomalous difference fourier maps from data > collected above and below the sulphur edge (lambda ~5 A) to answer your > question. > > We’ve published some test crystal work around the sulphur edge a while > ago, you might want to have a look here: > https://doi.org/10.1016/j.nimb.2016.12.005 > > The beamline is currently in an advanced commissioning phase accepting a > limited number of projects. So, please get into touch if you are > interested. We are currently sorting out a few more hardware and software > aspects before we can run the beamline as a standard user facility, but we > have made a lot of progress over the past months. There will be more > details here on the bulletin board ahead of the next call for proposals in > autumn. > > Best regards, > > Armin > > > Postdoc position for long-wavelength crystallography: > https://vacancies.diamond.ac.uk/vacancy/post-doctoral- > research-associate-355285.html > > > > > On 31/07/2018, 14:38, "CCP4 bulletin board on behalf of David Schuller" < > CCP4BB@JISCMAIL.AC.UK on behalf of schul...@cornell.edu> wrote: > > How can one distinguish between a sulphate or phosphate in an electron > density map? Both are present in the mother liquor, and resolution is > in > the range of 1.75 - 2.25 A > > > -- > ============================================================ > =========== > All Things Serve the Beam > ============================================================ > =========== > David J. Schuller > modern man in a post-modern world > MacCHESS, Cornell University > schul...@cornell.edu > > ############################################################ > ############ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 > > > > -- > This e-mail and any attachments may contain confidential, copyright and or > privileged material, and are for the use of the intended addressee only. If > you are not the intended addressee or an authorised recipient of the > addressee please notify us of receipt by returning the e-mail and do not > use, copy, retain, distribute or disclose the information in or attached to > the e-mail. > Any opinions expressed within this e-mail are those of the individual and > not necessarily of Diamond Light Source Ltd. > Diamond Light Source Ltd. cannot guarantee that this e-mail or any > attachments are free from viruses and we cannot accept liability for any > damage which you may sustain as a result of software viruses which may be > transmitted in or with the message. > Diamond Light Source Limited (company no. 4375679). Registered in England > and Wales with its registered office at Diamond House, Harwell Science and > Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom > > > ######################################################################## > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
