DFT study of gadolinium aluminohydrides and aluminofluorides

Highlights: • DFT calculations show superhalogen behavior for Gd(AlH4)4. • The electron affinity of Gd(AlF4)4 is 8.42 eV which is a hyperhalogen. • The significant HOMO–LUMO gaps indicate chemically very stable moieties. - Abstract: First-principles calculations using density functional theory were performed to study the structure, stability and electronic properties of clusters formed by attaching AlH4 and AlF4 complexes to the Gd atom. The calculated electron affinity of AlH4 is 3.58 eV, close to that of chlorine, and for the Gd (AlH4)4 cluster it is 4.95 eV, indicative of superhalogen behavior. For AlF4 the calculated electron affinity is 7.36 eV, indicating superhalogen behavior. When this complex is used to decorate Gd in number that exceeds its formal valence (+3) the electron affinity increases to 8.42 eV in the Gd (AlF4) 4 cluster, which is an indication of hyperhalogen behavior. High-spin ground states are predicted for these moieties, which have same spin multiplicities in both aluminohydrides and aluminofluorides