DIFFRACTION PATTERN

This allows the diffraction pattern produced by an arbitrary tri-clinic unit cell to be predicted (at present this assumes 360 degree rotation about a rotation axis). For the diffraction pattern to be predicted it is necessary to have defined the geometry of the experimental set-up; this must be done beforehand using GEOMETRY (EXPERIMENT) (See Section 15.43, Page ).

FIT2D calculates the position of the centre of each Bragg peak for a range of $hkl$ indices. The user is prompted for the cell parameters and for the range of indices.

The user is allowed the option of creating an overlay diagram of the predicted diffraction pattern on top of an image of the ROI.

(At present the unit cell interaxial angles are entered in a form different from the usual crystallographic conventions. If crystallographers are interested in this command the form of input can be changed.)