Chemical Crystallography

+ Frequently Asked Questions

+ Crystals Primer

+ Crystals User Guide

+ Crystals Manual

- Cameron Manual

1. Introduction

2. How To Get Started

3. Data Input

4. Outputting Data

5. Editing The Atom List

6. Obeying Files

7. Graphical Output Devices

8. View Direction Control

9. Include And Exclude

10. Drawing Style Control

11. Connectivity Control

12. Control Of Colour

13. Atom Labelling

14. Other Picture Controlling Commands

15. Symmetry Input

16. Crystal Packing Commands

17. Add And Move - Further Symmetry Related Commands

18. Distance And Angle Calculations

19. Information On Data Held Within The Program

20. Group Definitions

21. Miscellaneous Commands

22. How To Stop The Program

23. Menu Definition File

24. Some Useful Ideas

+ Index

Fri Jun 2 2000

Cameron Manual

Chapter 13: Atom Labelling



The LABEL and NOLABEL commands control the atom labelling. They are set up in an identical way to INCLUDE and EXCLUDE and the syntax is identical :-


are all valid. Note that atoms will not be labelled if they are not included in the picture.

All atoms will be labelled if the LABEL command has been used for them. The label positions can be altered using the mouse if required. Note that label positions are recalculated if atoms are included or excluded or a change in the view direction has occurred. Therefore, it is advisable that the 'final' view is obtained before labels are positioned with the mouse.

Mouse labelling is controlled as follows. The user clicks on a position on the screen (once the message Mouse Labelling activated has been seen). If this position is over a label then the label is replaced by a box of the same size as the label. A red cross is drawn over the atom that the label refers to to aid identification. The mouse is then used to position the TOP LEFT HAND CORNER of the label by a second click. Alternatively, hitting the N key (for Nolabel) will remove the label altogether.

If the mouse is clicked on an atom which is NOT labelled then a label will appear at the atom centre, this label can then be moved as described above.

If at any time the user wishes to view the current picture without releasing the mouse, this can be done by hitting the 'V' key.

These commands relate to the pack number display while labelling. Atoms are assigned a pack number after PACK or ENCLOSURE. This number is then displayed as eg N1_5. These numbers are used to refer to atoms and elements as required. INITIAL (the default) will just display N1 which GENERATED shows N1_5.
CELL Controls the cell labelling.
FRAGMENT Allows the user to set labels for a given fragment.
This sets the point size of the font to be used in hardcopy output. It requires one argument.
DEFAULT This resets the point size to its default value of 12.

POSITION This allows the user to annotate a picture. The syntax is

TEXT "text string" POSITION x y

the text must be in quotes if it includes spaces. x and y are the position of the text in percentages from the top left hand corner of the diagram. After the text is processed it is assigned a number.
NUMBER The NUMBER command can be used to move a text item after it has been created by using TEXT NUMBER n POSITION x y.