Cohesive properties and electronic structures of face-centered (FCC) and hexagonal close-packed (HCP) phases of CrNiFe2Hx (x = 0, 2, 4) alloys have been studied using ah initio linear muffin-tin orbital method (LMTO). The cohesion energy of these crystalline phases has been calculated as a function of the Wigner-Seitz radius. The results of the electronic structure calculations were used to determine relative stability of different structures. The predicted structure and calculated equilibrium lattice constants are in good agreement with the experimental data. The nature of FCC --> HCP transformation in CrNiFe2 alloy during hydrogen charging is found to be due to the weakening of interatomic bond.