GroupSubgroup Correlation Relations 
The program calculates the correlation relations between the irreducible
representations (irreps) of a groupsubgroup pair. It takes into
account all the points of the reciprocal space which are reduced to the
Γ point in the low symmetry basis.
Using the program one can study the behaviour of the Raman modes during
phase transitions.
 INPUT:
One have to introduce the high and low symmetry structures and the
transformation matrix which relates both structures. If it is not known
that matrix one can use the program
STRUCTURE RELATIONS to
calculate it.
 OUTPUT:
 Raman modes for the high and low symmetry structure.
 Modes different from Γ which might contribute
in the phase transition.
 The correlation relations tables.
NOTE: The program only accepts, as input data, structures described in a standard/default setting of the space group. If the original structure is described with respect to an ITA setting, the program SETSTRU can be used to transform it to the standard setting. In the case of more arbitrary nonconventional settings, the tool TRANSTRU can be of some help, if the transformation to the standard setting is known.


