CONTOURED FOURIER MAP


MOLECULAR GRAPHICS TOOLS PLATON HOMEPAGE

Five contoured Fourier maps types are available

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 identical to those used by SHELXL.


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

MOLECULAR GRAPHICS TOOLS PLATON HOMEPAGE
27-Aug-2025 A.L.Spek