A comparative study of the effect of donor–acceptor defect pairs, [(In,Ga)Cu2+,2VCu-] on the unit-cell parameters, a, c and V, of the ordered defect compounds that were intermediate phases of the pseudo-binary [Cu2(Se,Te)]1−x[(In2,Ga2)(Se3,Te3)]x system was carried out. It was found that a, c and V decrease linearly with the increase in the fraction of cation vacancies to the total number of cation positions, m, or the fraction of the interacting donor–acceptor defect l per unit, respectively, in the chemical formula. The reduction in the unit cell dimensions was explained as due to the decrease in the effective cation radius reff caused by the increase in m or l or decrease in n. The linear dependence of reff on a, c, and V has important consequences. This behavior could be used to predict the unit-cell parameters of other ODCs that may had chalcopyrite-related structure and had not been reported so far.

Effect of Donor–Acceptor Defect Pairs on the Crystal Structure of In and Ga Rich Ternary Compounds of Cu–In(Ga)–Se(Te) Systems. S.M.Wasim, C.Rincón, J.M.Delgado, G.Marín: Journal of the Physics and Chemistry of Solids, 2005, 66[11], 1990-3