EMDisorientations

Program: EMDisorientations

This is a simple utility program to compute the disorientations between two sets of orientations. The orientations are assumed to be two pairs of Euler angle triplets (in the Bunge convention), and the program will return a file with the original orientations as well as the misorientation angle and axis for each pair, including a reduction to the Rodrigues fundamental zone of the stated point group.

The program uses a name list file, and the template can be obtained in the usual way: EMDisorientations -t. Rename this file to EMDisorientations.nml and edit it:

 &Disorientations
! name of input text file with two sets of three columns (six columns per row) 
! of Euler angles (degrees)
 inputfile = 'undefined',
! name of output text file with disorientations
 outputfile = 'undefined',
! point group number
 pgnum = 32,
 /

Both file names are relative to the EMdatapathname path; the point group is a number between 1 and 32, and is used to identify the Fundamental Zone to be used for the computations.

As an example, consider the following input file with two pairs of Euler angle triplets:

2
60.0 45.0 60.0 60.0 45.0 0.0
10.0 20.0 30.0 40.0 50.0 60.0

Using cubic symmetry (point group 32), the output of this program becomes:

      2
   60.000 45.000 60.000 60.000 45.000 270.000 30.000 0.000 -1.000  0.000
   10.000 20.000 30.000 40.000 50.000 330.000 47.866 0.366 -0.616 -0.697

Note that some of the original angles have been replaced by equivalent orientations inside the Rodrigues fundamental zone. Column 7 contains the disorientation angle, and columns 8-10 are the direction cosines of the rotation axis.