Effects of single- and co-substitution of Ti on dehydrogenation of Mg2NiH4: A first-principles study

The optimized crystal structure of (a) Mg16Ni8H32, (b) Mg15TiMg3Ni8H32, (c) Mg16Ni7TiNiH32 and (d) Mg15TiMg3Ni7TiNiH32. The enlarged pictures of TiH polyhedron and the adjacent NiH polyhedrons are also shown, together with the NiH bond lengths of typical Ni(6)H tetrahedron.194