Crystal structure of τ5-TiNi2−xAl5 (x = 0.48) and isotypic {Zr,Hf}Ni2−xAl5−y

► Crystal structure of τ5-TiNi2−xAl5. ► τ5-TiNi2−xAl5 is isostructural with the ZrNi2Al5 type. ► Relationship among the structure types of Cu, TiAl3, ZrNi2Al5 and Zr(Ni,Ga)7. ► TEM data assured the unit cell dimensions, the crystal symmetry. ► Combined refinement of XPD and NPD data confirmed the full atom.