In this work we have realized a simplified model to analyze compositional inhomogeneities in commercial hydrogen storage alloys. We have used it to evaluate the effect of the thermal annealing, together with calorimetric, PCIs and XRD measurement. We have compared results with composition distribution histograms based on Rietveld refinement of XRD patterns. Finally we studied the variation of α and β phases crystallographic parameters with H2 pressure.