Abstract
First principles calculations using gradient corrected density functional theory with B3LYP method reveal the unusual properties of a Nickel (Ni) atom interacting with fluorine (F) atoms. Up to six F atoms are bound to a single Ni atom, which results in increase of electron affinities as successive fluorine atoms are attached, reaching a peak value of 8.85 eV for NiF6. The large HOMO-LUMO energy gap, both in neutral and anionic form, further provide evidence of their stability. These unusual properties brought about by involvement of 3d and 4p-electrons, which not only allow NiFn (n = 1 - 6) clusters to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 1-3.