On Thursday, April 05, 2012 10:48:16 am Oliver Smart wrote:
>
> On Thu, 5 Apr 2012, Ethan Merritt wrote:
>
> > On Thursday, April 05, 2012 09:30:25 am Phil Jeffrey wrote:
> >> Fc doesn't contain the weighting scheme used in the creation of the map
> >> coefficients, so Fc would require some sort of program to be run to
> >> recreate those for both 2Fo-Fc and Fo-Fc maps.
> >
> > The viewers I am familiar with do this for themselves on the fly.
> > No need to involve additional programs. In fact, generating and storing
> > map coefficients is not part of my work flow, since none of the programs
> > I normally use need them to be pre-calculated.
> >
>
>
> Ethan,
>
> If you load a mtz file from refmac or BUSTER then this file contains Map
> Coefficients. Different programs and protocols produce different maps.
I am bowing out of this discussion with apologies for any confusion that
I caused.
I have realized that there may be a generational difference in
understanding the term "map coefficient" (or else my poor brain is just
not functioning as well as it ought to). I thought that the proposal was
to require depositing the equivalent of a ccp4 *.map file, i.e. the
real-space side of the Fourier transform. I see now that people are
using "map coefficient" to mean "weighted F", which was not what I originally
understood.
please carry on!
Ethan
> So
> I second Phil's comment that including map coefficients in deposition is a
> really good thing. It will enable people to see exactly the maps as seen
> by the depositor (and to do so in a few years time). Hence we have
> included map coefficients in 3 recent depositions 3syu, 3urp, 3v56 (using
> a prototype mtz2cif tool that is not quite ready for release yet).
>
> We have also worked out how to patch ccp4 cif2mtz so that it can do the
> reverse process see
>
> https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ccp4bb;325e1870.1112
>
>
> Regards,
>
> Oliver
>
--
Ethan A Merritt
Biomolecular Structure Center, K-428 Health Sciences Bldg
University of Washington, Seattle 98195-7742
