Instruction for using squeeze of platon



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Quick Start Users Guide for  

Bruker SMART APEX II Diffractometer 

 

APENDIX III 

 

INTRODUCTION FOR FINDING ADDITIONAL SYMMETRY 

WITH PLATON 

 

J. Tanski 2/12/06 

 

 



Platon is a versatile SHELX97 compatible multipurpose crystallographic tool and is 

FREE for academic users.  More information can be found from Platon homepage. 

 

Suppose your files are f10.* 



 

(1) 


In DOS mode, type  copy f10.res f20.res, and then type  copy f10.hkl f20.hkl.  In 

this introduction, f20.* will be used while f10.* will be kept for backup. 

 

(2) 


Find the Platon program on the computer, double click pwt.exe to open Platon 

Taskbar and the following window will show up. 

 

 

 



(3) 

In Platon, click  File  and select  select Data File.  Either .ins or .res file can be used.  

However,  .res file is recommended.  Click  Files of type  and select  SHELX file 

(*.res), then find the target file  f20.res  by browsing the computer through the  

Look in window, then click  open  to select  f20.res  file. 

 

(4) 



Find the icon 



fx

on the toolbars and click it.  A lot of numbers will come out on 

the screen at this time and it usually takes a few seconds but up to a couple of 

minutes.  It’s done when you see the bottom of the screen have something like 

following: 

 

 



 

 




Summary and Remarks : N = NOTE, W = WARNING, E = ERROR 

 

You may see the summary of results from Platon on the screen. 



 

(5) 


Close Platon program and any other windows that were opened by Platon. 

 

(6) 



Use Windows Explorer to go to the directory of your files and double click  f20.lps  

to open it.  Go to the end of this file and find lines of  (Summary and Remarks : N 



= NOTE, W = WARNING, E = ERROR).  Pay attention to those warning 

messages.  If additional symmetry was found, you will see a message like this: N: 



ADDSYM finds additional \(pseudo\)symmetry in the structure \(please 

check!\).  Check that there are no solvent accessible voids; if there are, there may be 

disordered solvent that can be modeled or treated with SQUEEZE.  PLATON also 

tells your about possible hydrogen bonds; if there are, insert HTAB in the .ins and 

run XL again.  Close f20.lps. 

 

(7) 


If no additional symmetry was found, finish the structure as usual using files f10.*.  

Otherwise, the structure needs to be converted to the proper space group.  In Platon 

Taskbar, select the data file again click  Start  and select  Graphical Menu.  A 

graphical menu will show up. 

 




 

 

(8) 



Under the column of  SYMMETRY, click  ADDSYM-SHX  and wait for a few 

seconds until it’s done.  Platon will make changes to  f20.res  file.  Then click  Exit  

on the right bottom corner to exit graphical menu.  Close Platon program and any 

other windows that were opened by Platon. 

 

(9) Open 



 

f20.res  with Notepad.  The title has been changed to this: 

 

 



TITL XXXXXX in P-1                  P21/c 

 

The first P-1 is the previous space group and P21/c is the new space group.  Change 



the title properly by deleting previous space group P-1. 

 

Sometimes, Platon uses non-standard settings.  For example in this case, P2(1)/c  



should be used instead of  P2(1)/n.  Make sure that the new space group is correct 

by referring to the new symmetry operations. 

 

(10)  SFAC and UNIT lines have been changed to: 



 

 

SFAC  C   2.31000  20.84392   1.02000  10.20751   1.58860   0.56870   0.86500 = 

         51.65125   0.21560   0.00330   0.00160    11.500   0.68000  12.01000 

SFAC  H   0.49300  10.51091   0.32291  26.12573   0.14019   3.14236   0.04081 = 

         57.79977   0.00304   0.00000   0.00000     0.624   0.35000   1.00800 



UNIT    92   60 

 

Manually create SFAC lines to be  SFAC C H, and make sure the order of atom is 



the same as in atom list.  Put this line just before  UNIT  instruction as usual.  

Delete current SFAC lines with a lot of numbers.  New SFAC and UNIT lines 

should look like this: 

 

SFAC  C H 

UNIT  92  60 

 

IMPORTANT !  



Several things have been changed from the initial .res file to that output by 

Platon.  Make sure all commands present in the saved f10.res are copied 

appropriately into the new f20.res. 

 

Platon may also change the atom codes in the atom list, make sure to fix these! 

 

Save f20.res after change and then quit. 






 

 



(11)  In DOS mode, type  copy f20.res f20.ins  to create f20.ins file. 

 

(12)  In DOS mode, type  copy f10.pcf f20.pcf  to create f20.pcf file.  .pcf  file contains 



crystal information needed as a reference when  XCIF  runs.  Open  f20.pcf  with 

Notepad, check  _symmetry_cell_setting  and  



_symmetry_space_group_name_H-M  at the beginning of the file. 

In this case, change  _symmetry_cell_setting   from  Triclinic  to  Monoclinic;  

Change  _symmetry_space_group_name_H-M  from  P-1  to  P2(1)/c.  Save 

f20.pcf and quit. 

 

(13)


 

In DOS mode, run XL f20.  Now the structure is in the new symmetry.  Finish as 



usual.  During XCIF, make sure the correct space group name is printed. 

 

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