I forgot to say in my email about the program AnoDe that of course it
also uses the FA values from the SHELXC output file name_fa.hkl as the
amplitudes for the 'heavy atom map' with phases (native-alpha). This
procedure is remarkably simple and effective.
George
On Thu, Jul 07, 2011 at 09:46:37AM +0200, George M. Sheldrick wrote:
> Dear Jacob,
>
> Andrea Thorn and I will be demonstrating such a program (called AnoDe) at
> the Software Fayre at the IUCr Meeting in Madrid and it is already available
> from my beta-test site on email request. AnoDe requires only two input
> files: a PDB file of the refined structure and the name_fa.hkl file from
> SHELXC that includes the phase shift alpha that is added to the heavy atom
> phase to get a starting value for the native phase in experimental phasing
> by SAD, MAD, SIRAS etc. Anode determines the heavy atom substructure phase
> by subtracting alpha from the native phase that it calculates from the PDB
> file. The resulting 'heavy atom density' is summarised in a variety of useful
> ways and a file is written for Coot to display it. The advantage of this
> extremely simple approach is that it can be used for SAD, SIR, SIRAS, MAD
> and RIP phase information and that apart from SHELXC no other program,
> library, environment etc. are required.
>
> Best wishes, George
>
>
> On Wed, Jul 06, 2011 at 11:46:14AM -0500, Jacob Keller wrote:
> > Dear Crystallographers,
> >
> > it seems to me that for clearly identifying/characterising anomalous
> > scatterers for a solved structure, one could make a map using two
> > datasets: one at the f" peak, one low energy remote. One would then
> > use the signal both from the Bijvoet differences in the peak dataset
> > plus the differences between the peak and low-energy datasets, which I
> > think I have seen called "dispersive" differences. I guess this would
> > be like a MAD map, but using pre-existing model phases--is there such
> > an animal in the software, or would it even be helpful?
> >
> > Jacob Keller
> >
> > --
> > *******************************************
> > Jacob Pearson Keller
> > Northwestern University
> > Medical Scientist Training Program
> > cel: 773.608.9185
> > email: [log in to unmask]
> > *******************************************
> >
>
> --
> Prof. George M. Sheldrick FRS
> Dept. Structural Chemistry,
> University of Goettingen,
> Tammannstr. 4,
> D37077 Goettingen, Germany
> Tel. +49-551-39-3021 or -3068
> Fax. +49-551-39-22582
>
--
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-22582
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