RaDMaX (radiation damage in materials analysed with X‐ray diffraction) is a user‐friendly graphical program that allows the determination of strain and damage depth profiles in ion‐irradiated crystals. This task is achieved by fitting experimental X‐ray diffraction data, recorded in symmetrical θ–2θ geometry, with a dynamical diffraction model parametrized with variable strain and damage profiles based on B‐spline functions. The strain and damage profiles can be graphically manipulated so as to fit the calculated curve to the experimental data. Automatic fitting procedures (generalized simulated annealing and conventional least squares) are also implemented. RaDMaX is free and open source (CeCILL licence) and can be downloaded from http://aboulle.github.io/RaDMaX.

Structures of compounds in the Cu 2 Se-In 2 Se 3-Ga 2 Se 3 system have been investigated through X-ray diffraction. Single crystal structure studies for the so-called stoichiometric compounds Cu(In,Ga)Se 2 (CIGSe) confirm that the chalcopyrite structure (space group I4¯ 2d) is very flexible and can adapt itself to the substitution of Ga for In. On the other hand a structure modification is evidenced in the Cu 1Àz (In 0.5 Ga 0.5) 1+z/3 Se 2 series when the copper vacancy ratio (z) increases; the chalcopyrite structure turns to a modified-stannite structure (I4¯ 2m) when zZ0.26. There is a continuous evolution of the structure from Cu 0.74 (In 0.5 Ga 0.5) 1.09 Se 2 to Cu 0.25 (In 0.5 Ga 0.5) 1.25 Se 2 ((i.e. Cu(In 0.5 Ga 0.5) 5 Se 8), including Cu 0.4 (In 0.5 Ga 0.5) 1.2 Se 2 (i.e. Cu(In 0.5 Ga 0.5) 3 Se 5). From this single crystal structural investigation, it is definitively clear that no ordered vacancy compound exists in that series. X-ray photoemission spectroscopy study shows for the first time that the surface of powdered Cu 1Àz (In 0.5 Ga 0.5) 1+z/3 Se 2 compounds (za0) is more copper-poor than the bulk. The same result has often been observed on CIGSe thin films material for photovoltaic applications. In addition, optical band gaps of these nonstoichiometric compounds increase from 1.2 to 1.4 eV when z varies from 0 to 0.75.