New Platon Addsym web tutorial for finding missing symmetry

Lachlan Cranswick l.cranswick at
Sun Jan 7 03:51:13 EST 2001

For those who don't normally check for updates often on the 
crystallographic software they use, following is an example
why this may be a good thing to do, especially with Ton Spek's

"Why you should keep updating your version of Platon and another 
ADDSYM example of why Platon/Addsym should be considered a 
mandatory program for all crystallographers"

The recent versions of Platon have been updated with respect to
the Addsym algorithm now handling 1/2,1/3,1/4,1/8, etc, subcells.

The above tutorial uses an example starting structure in P1 with 
"96" independent Carbon atoms.

 The pre November 20th, 2000 version of Platon's Addsym would find
 a P-1 half cell  ("24" independent Carbon atoms) 

 However, the newest Addsym within Platon will now find the best
  cell as being P 21/C -  1/8 subcell: ("3" independent Carbon atoms) 

Structure files are also included in Shelx format for those
who would like to try this out.  Using Addsym within Platon is
highly trivial, i) Load file, ii) click Addsym button, iii) be


Also refer:

PLATON/ADDSYM analysis of all 1970 Cc structures in the CSD (apr 1999):
        CCP14 Canadian Mirror 

PLATON/ADDSYM analysis of all 1848 P1 structures in the CSD (Oct 1999):


For UNIX users:

UNIX Script for semi-automatic download and Compilation of Platon


Platon - (with Pluton/Addsym/Sqeeze/System S) for UNIX by Ton Spek:
Platon Download:


Hints on compiling/installing platon for UNIX/Linux/FreeBSD:


Platon for Windows (ported by Louis Farrugia:)


giving free access to UK students and academics to all the main
structure databases - MDF, ICSD, Cambridge (as well as other 
relevant databases related to chemistry)

Platon is installed on - and is invoked by typing:

   platon  filename.ins  (or res, cif, pdb or spf)

(primarily for using Platon as a user friendly front end for 
"quest" to do Cell and Connectivity searches on the Cambridge 

For Windows users needing freeware X-servers, refer:

Secure MS-Windows to UNIX machines based X-Sessions via 
Secure Shell Tunnelling:
(Using Teraterm for Windows and MI/XServer v 5.6 as an example)


Lachlan M. D. Cranswick

Collaborative Computational Project No 14 (CCP14)
    for Single Crystal and Powder Diffraction
Daresbury Laboratory, Warrington, WA4 4AD U.K
Tel: +44-1925-603703  Fax: +44-1925-603124
E-mail: l.cranswick at  Ext: 3703  Room C14

After 10th January 2001 - visiting:
   CSIRO Division of Minerals, Bayview Ave, Clayton, 
       Melbourne, Victoria, Australia, 3168

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