First principles investigations of the hydrogenation effects on the electronic structure and the chemical bonding of CeIrAl

► Hydrogen positioning in CeIrAl from ab initio leads to its coordination within Ce3Ir tetrahedra. ► Interpreting the experimental findings of Ce valence change intermediate → trivalent in CeIrAlH2. ► Hydrogen charge: −0.39. It is weakly bonded in the intermetallic substructure. ► The results allow assessing the reversibility of hydrogen absorption/desorption in CeIrAl.