The thermodynamic model proposed by Miedema is capable of predicting the enthalpy of formation (Delta H) and relative stability of phases in binary but not in ternary or multi-component systems. While developing nanocrystalline binary/ternary metal hydrides for compressor-driven reversible heating-cooling applications, it is necessary to identify appropriate alloy compositions with suitable hydrogen storage capacity and reversible hydrogen absorption-desorption capability. Accordingly, a suitable modification of the Miedema model is proposed in the present study for calculating Delta H of AB(2) type of pseudo-binary (Ti-Zr)(Fe-Cr)(2) and pseudo-ternary (Ti-Zr)(Fe-Cr)(2)-H alloys. Subsequently, Gibbs energy (Delta G) of the possible phases is estimated to predict relative phase stability/equilibrium in a given system. It is shown that grain size or interfacial energy contribution exerts a significant influence on Delta G and relative stability of the phases beyond a critical value/limit. Finally, the predicted phase equilibrium from this model-based calculation is validated by suitable comparison with relevant experimental data reported in the literature.