CONTOURED FOURIER MAP


MOLECULAR GRAPHICS TOOLS PLATON HOMEPAGE

Five types of Fourier maps are contoured

Structure factors are calculated based on the model in the '.ins' file.

OMIT instructions prior to the map calculation allow for the omission of the named atoms from the structure factor calculations.

Example : 'OMIT O1 O2'

Scattering factors used in the calculations are indentical to those used by SHELXL97.


INTRODUCTORY EXAMPLE

In order to draw contour maps two data files will be required.
  1. A file containing the structural parameters.

    This can be a

  2. A file containing reflection data.

    This can be a


Example data for the worked example, C10H12O6, given below are cdemo.cif and cdemo.fcf

Invoke PLATON with these two files with platon cdemo.cif

Click on the PLATON opening menu on the option 'CONTOUR-Fo'.

Three points can now be entered to specify the desired general plane in the Fourier map to be contoured.

As an example enter the points O501, C501 and O502 respectively.

The result of the calculation is shown in Fig. 1

The menu on the right side of the plot now gives various option for subsequent plots.

The next layer (0.3 Angstrom above the previous one will be shown by clicking on the 'Up' button.

The view window can be moved in the horizontal and vertical directions or rotated over an angle or made larger and smaller in order to 'window out' the area of interest.

Example: click in the rightest box of 'Vert Shift' and The middel box of 'VertAngSize'. The result will be Fig. 2.

Note:


Contour Menu Options

  1. Patterson Map
  2. Fo-Map
  3. 2Fo-Fc-Map
  4. Diff-Map
  5. SQUEEZE-Map
  6. Plane-TNCP
  7. Plane-abcd
  8. Plane-Bisect
  9. Plane-Perp
  10. PlaneXYYZXZ
  11. PlaneDisTol
  12. VertAngSize
  13. Horiz Shift
  14. Vert Shift
  15. Z-Rotation
  16. Bonds
  17. Label -Hat+
  18. Ch-Step-Siz
  19. Ch-Cntr-Lev
  20. Def-Cntr-Lv
  21. XR, YR, ZR Rotations
  22. OmitFromSFC
  23. Decoration
  24. Up Down
  25. EPS End

MOLECULAR GRAPHICS TOOLS PLATON HOMEPAGE
8-may-2000 A.L.Spek