The "Simulation" pulldown menu:


Before compute a simulation select the options in the following menu:

  • h, k and l are the limits for the absolute maximum values of spots indexes. This define a parallelepipede in the reciprocal space. The program will draw only the spots corresponding to nodes included inside the larger sphere contained in the parallelepipede.

  • It is also possible to fix the minimum and maximum values for the wavelength of the X-ray beam (in Angstrom).

  • The bottom part of this menu is displayed only when computing the intensities. Select the various factors taken into account for this computation. They are similar to those described in the paper of E.Preus

    When the polarization factor is taken into account one must also click the "Polarization options" button which directs to the sub-menu:

    One must indicate if the X-ray beam is polarized. In such case, give the polarization componant perpandicular to the horizontal plane, i. e. along the Oz axis, and the componant parallel, i. e. along the Oy axis.


    This starts the computation of a simulated diagram. It may need some time, depending on the options (with or without computation of spot intensities) and the speed of your computer: please wait.


    This button enables to choose options used for display and print of the diagram, by means of the menu:

  • The size of Bragg spots may be any one of four predefined sizes (Small, Medium, Large, Huge) simply by clicking on the corresponding button.

  • Indexes values will be written on the diagram if their absolute values are smaller than the limits h,k and l given in this menu. By default no indexes value is printed.
    A title may be written at the top of the simulation.

  • In the case when intensities of spots are computed, the size of the spots is modulated according to their intensity.
    The first cursor is used to modify the slope of the densitometric curve of the detector (photographic film).
    The other cursor is used as a threshold value: spots corresponding to lower intensity are not represented. By default all spots are drawn.


    This button is used to save a simulation as a Postscript file, or to print it directly on a printer.

  • "To file" option:

    A selection box is displayed:

    Type a new filename in the "Selection" field. By convention, it is recommanded to use a name with the extension .ps. Then click on "OK".

  • "To printer" option:

    Give the print command to use on your system. Then click the "OK" button.

    "Write log":

    To keep an history of all parameters and results of the simulation you may create a log file by selecting this button.
    The log file will contain information such as: cristallographic data, type of X-ray source, options for indexation, simulation and display, transformation matrices and the list of all visible Bragg spots (including harmonics) with their coordinates, wavelength ...etc.