chem cryst
Home
-Crystals + Research Contact Lectures + Links + Gallery CSD installation Chemistry Dept Division University of Oxford chem cryst news |
Cameron ManualChapter 18: Add And Move - Further Symmetry Related CommandsThe PACK and ENCLOSURE commands already detailed allow the user to apply all of the symmetry operators in the spacegroup to the initial set of atoms in order to get a fully 'packed' result. In some cases however, the user may wish to apply only one symmetry operator or to apply ones that are not present in the spacegroup. The ADD and MOVE commands allow this. [Top] [Index] Manuals generated on Wednesday 8 November 2006 18.1: ADDThe ADD command allows the user complete control over the symmetry operator used to generate new atoms. The first task of the user is to generate a list of those atoms to be used in the symmetry generation later. One of the following sub-commands is required :- ATOMS
The names of atoms to be included in the pack list are specified here. Element names can also be used if required. ALL
ALL refers to the atoms that are in the current list. If any atoms have been generated by previous PACK , ENCLOSURE or ADD commands then these will all go into the list. INITIAL
ADD INITIAL means that the only atoms to go into the ADD list are those that were initially input. GROUP
This is followed by a group name. The group must have been previously been defined by the command DEFGROUP. Once the ADD list has been created the user must then supply the symmetry operators which will act on the atoms in this list to generate the new atoms. The symmetry input is in two parts. OPERATOR
The symmetry operator may be input in decimal or fractional form eg
x y+1/2 z -0.333-x -y -z ETC
X + 1/2 -Y Z
TRANS
Translations can also be applied if required. The translations
are
applied in unit cell fractions. The syntax is :-
TRANS x y z
[Top] [Index] Manuals generated on Wednesday 8 November 2006 18.2: EXAMPLESADD ATOMS C1 OPERATOR X+1/2 Y Z
ADD ATOMS C1 TRANS 0.5 0 0
ADD ALL TRANS 1 0 0
ADD ALL TRANS 0 1 0
ADD INITIAL TRANS 0 1 0
[Top] [Index] Manuals generated on Wednesday 8 November 2006 18.3: MOVEThe syntax for this command is identical to that for ADD. Therefore the commands available are :- ATOMS
ALL
GROUP
INITIAL
Which must be followed one (or both) of :- OPERATOR
TRANS
The MOVE command applies a symmetry operator and/or a
translation to
all of the atoms held in the list defined by the
ATOMS/ALL/GROUP/INITIAL
commands. Unlike ADD therefore, the same number of atoms are
present at
the beginning and end of the operation.
[Introduction | How To Get Started | Data Input | Outputting Data | Editing The Atom List | Obeying Files | Archiving And Retrieving Views | Graphical Output Devices | View Direction Control | Include And Exclude | Drawing Style Control | Connectivity Control | Control Of Colour | Atom Labelling | Other Picture Controlling Commands | Symmetry Input | Crystal Packing Commands | Add And Move - Further Symmetry Related Commands | Distance And Angle Calculations | Information On Data Held Within The Program | Group Definitions | Miscellaneous Commands | How To Stop The Program | Menu Definition File | Some Useful Ideas ] |
© Copyright Chemical Crystallography Laboratory, Oxford, 2006.
Comments or queries to David Watkin -
david.watkin@chem.ox.ac.uk Telephone +44 1865 285019.
This page last changed on Wednesday 8 November 2006.
The website was re-generated on Wednesday 8 November 2006.
Choose your nearest mirror for faster access:
[ Original
|
CCP14 UK Mirror
|
CCP14 Canadian Mirror
|
CCP14 USA Mirror
|
CCP14 Australian Mirror
]
Authorised people, edit:
this file,
news,
tree,
template,
stylesheet.
Rebuild website.