In order to experimentally try out a new generalized X-ray diffraction theoretical model [A. Sanz-Hervas et al., J, Appl. Phys. 82 (1997) 3297], we have carried out a detailed analysis of high-resolution X-ray diffraction measurements of AlAs/Al0.5Ga0.5As/GaAs single quantum well structures with a nominal well width of 100 Angstrom grown side-by-side on (1 1 1)A, (1 1 2)A, (1 1 3)A, (1 1 4)A, (1 1 0) and (0 0 1) GaAs substrates by molecular beam epitaxy. For each substrate orientation we have measured various symmetric and asymmetric reflections at different azimuths which were fitted by diffraction curves obtained through the theoretical model that was being tested. The HRXRD study enabled us to study the crystal quality and the main structural parameters of the samples. We achieved an excellent agreement between the measurements and the simulated curves by using a single set of structural values for each substrate orientation. This proves the validity of our simulation model to analyze high-resolution X-ray diffraction measurements of epitaxial structures grown on (1 1 n) substrate orientations.