a modul of JSV1.07  
© Steffen Weber 1999

XRDL - reciprocal space viewer

The basic idea is that XRDL allows real time rotations of the reciprocal lattice points (3D diffraction pattern) whereby you may switch to the Laue mode or simply watch the corresponding "0.layer" as in precession photographs or elecron diffraction patterns. The color and radii of the reflections may be chosen to be either uniform, ~F*F, ~F or ~ Sqrt(F) where F is the structure factor.

The rotations are done by dragging the mouse (with pressed left/right mouse button) over the canvas, by using the cursor keys or by selecting a value from the menu.

Double clicking at the display area switches to a stick diagram for the 2theta distribution for the prsent data an the specified wavelength. Individual intensities are summed up for each occurring 2theta value. This diagram always shows the range [0-180]. Zooming is not supported here. Furthermore the indices of the strongest contributing reflection for each stick are given.

• 3D/2D X-ray diffraction patterns with real time rotation and layer scanning
• imitate the 0.layer while rotating (corresponds to Precession photo or Electron diffraction pattern)
• rotate the "crystal" while seeing the effect in a real time Laue simulation (transmission, backreflection)
• various possibilities to modify color and radii of the reflections
• reflection labels possible (hkl, Intensity, spacing, theta)
• you may click at a reflection to set it as orientation vector (from menu OPTION)
• output of PostSript and GIF (GIF routine by Jef Poskanzer, www.acme.com)
• direct printing support under Windows/Solaris (raster image)
• Bragg position diagram (double click on display area)
• SWING user interface

The *.xrd files look like this:

[xray] 1.54183
[cell] 2.47 2.47 6.93 90 90 120
[text] Graphite
 0  0 -2 481.1457
 0  0  2 481.1457
-3  2 -2   2.6948
 3 -1  2   2.6948
 0  0  0

xray: the wavelength is used to calculate theta and spacings d as labels for the 3D mode (precession, electron diffraction). In the Laue mode the theta values are calculated from the orientation of a (hkl) plane and not from the given wavelength.

cell: a b c [Angstroem] alpha beta gamma [deg] or [rad] !!!

text: any text you want to be displayed on screen and in the printout (1 line)

data: h k l Intensity

Note: The last reflection has to be "0 0 0" as a marker for the end of the data block !