Hi Mike,

If it is just a matter of computing a Fourier transform that is easy. Chimera already has libraries that does that. The trouble will be parsing the CIF file. Chimera reads molecular structure CIF and mmCIF files using a third party library called mmLib. I don't know if mmLib will read the structure factors. If you send me an example CIF file with structure factors I'll give it a try.

Tom

-------- Original Message --------
Subject: Re: [Chimera-users] Centro-symmetric space groups
From: Michael Day
To: Tom Goddard
Date: 9/4/09 12:41 PM

Hi Tom,

...

If I had to lobby for any particular ticket on your list it would be #201. What I would add in way of description on that ticket is that I'm not talking about using SHELX in Chimera. What I meant to say is for Chimera to read a standard format CIF file containing the reciprocal space transform of the real space electron density. The fft routines to transform back to real space have been around forever and are in most all modern languages.

All crystallography packages can write this type of file containing h,k,l F(obs)^2^, sig(F(obs)^2^), F(calc) and phi (phase angle in degrees). This the preferred format for sending data to the PDB.

I'm not looking to add a bunch of "stuff" to your already huge pile but I thought most of this was already in the public domain. After all, nothing is impossible for the guy that doesn't have to do it. It's all easy and straightforward, right? ;0)

As for the issue of reading the CIF, P21/n is a very common alternate setting of P21/c and the PDB symmetry list does not contain it.

Thanks again!!

Cheers,

Mike

<<< ------------------------------------------------------------------------>>>

Dr. Michael W. Day

Director - X-ray Crystallography Lab & Molecular Observatory

California Institute of Technology

Mail Code 139-74

Pasadena, CA 91125

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