Quantum mechanical calculations of the electronic structure of hydrogen storage materials have undoubtly deepened our fundamental understanding of their basic properties. In addition, ab-initio calculations can provide a useful insight on the hydrogen storage properties that are crucial for applications. In this paper, we focuss on the latter aspects, we discuss the electronic and elastic properties of Haucke compounds of AB5 type (A=La or Y, B=Ni), in relation with their hydrogen absorption properties. The effects of substitutions of Ni by an s element of the 3d series, Cu, as well as by s-p elements of the IIIA (Al) and IVA series (Si, Ge, Sn) for several substitution rates are presented. and discussed in light of available experimental data on electronic, thermodynamic and elastic properties.