Drastic changes in electronic, magnetic, mechanical and bonding properties from Zr2CoH5 to Mg2CoH5

► Zr2CoH5 and Mg2CoH5 show contrasted electronic, magnetic, mechanical and bonding properties. ► Zr2CoH5 is found more cohesive, harder and less ductile than Mg2CoH5. ► Metallic ferromagnet Zr2CoH5 in contrast with non-magnetic and insulating Mg2CoH5.