Generating LARGE Cartesian Lattices?

Artem Evdokimov AEVDOKIMOZ at cinci.rr.com
Thu Oct 17 08:03:13 EST 2002


Uncle Al,

Perhaps one could devise a cyclic script to use one of the CCP4 programs
iteratively in order to generate pieces of the lattice which then get merged
into one huge thing. Can you run CCP4 where you're at ?

Artem


"Uncle Al" <UncleAl0 at hate.spam.net> wrote in message
news:pgpmoose.200210162204.6584 at net.bio.net...
>
> Saco wrote:
> >
> > Have you checked Mercury?
> > http://www.ccdc.cam.ac.uk/prods/mercury/index.html
> > It can read .cif and save as .mol, but I'm not sure that's what you
> > are looking for.
>
> My needs as stated are very specific.  Given the crystal strucure of
> elemental tellurium, ICSD 65692.CIF (fractional coordinates), generate
> an (unordered) *.XYZ list of Cartesian coordinates for a given radius
> (or number of unit cells in each direction x,y,z).  Almost any crystal
> software package will do this, ORTEP to ATOMS.
>
> The *problem* is that I need a 120-150 A radius, or about 250,000
> atoms (about 9 MB of output).  Loathsome fat, stupid, and incapable
> Windows freezes solid at those memory requirements if any attempt is
> made to order the list or output in a window instead of a scratch
> file.  I have exhausted obscenities in seven languages damning
> BillGates to Hell
>
> Mercury is a very capable, very sophisticated package.  I'll give it a
> run.  I suspect I need a very primitive, very incapable program that
> just builds a lattice to a given radius.  I'm looking at crystallff.
> It could be the perfect tool!  Its extensive documentation very neatly
> omits giving even a single example of an input sequence.  I'm down to
> one fatal error.
>
> > The following link gives high-pressure Te structure.
> > http://cst-www.nrl.navy.mil/lattice/struk/Te.html
>
> "8^>)  I specifically need the helical P3(1)21/P3(2)21 hexagonal
> structure.
>
> > BTW, there has been recently a new solution proposed for the
> > crystallographic phase problem.
> > http://xxx.lanl.gov/abs/cond-mat/0209690
>
> Isn't that something?  It will be interesting to see if it is adopted
> as a general method.
>
> Thanks for the help.
>
> --
> Uncle Al
> http://www.mazepath.com/uncleal/
>  (Toxic URL! Unsafe for children and most mammals)
> "Quis custodiet ipsos custodes?"  The Net!
>





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