Fluorinated ferromagnetic metal clusters and their superhalogen behaviour

Abstract

Density functional theory calculations on the ground-state geometries and spin multiplicities of neutral and anionic ferromagnetic metal fluoride clusters, MFn (M = Fe, Co and Ni; n = 1–7), have been performed. The results show that in the case of FeFn and CoFn clusters, a maximum of five F atoms can be bound atomically to metal atoms while four in the case of NiFn. The remaining F atoms bind either very weakly or molecularly. The stabilities of all MFn clusters are discussed by calculating dissociation energies to F atoms and F2 molecules. We notice that the anionic species are relatively more stable than corresponding neutrals. The electron affinities of these clusters are very large, reaching values as high as 7.98 eV. Therefore, these clusters can be regarded as superhalogens.