Super and hyperhalogen behavior in MgX n and GdX n (X = F, BF4) clusters

New types of magnetic hyperhalogen compounds are theoretically characterized by density functional theory and hybrid functional for exchange-correlation potentials. A systematic study of the structure and geometries of neutral and anionic \(\hbox{MgF}_n, \hbox{Mg}(\hbox{BF}₄)_n ({n=1}\rightarrow 3)\), and \(\hbox{GdF}_n, \hbox{Gd}(\hbox{BF}₄)_n ({n=1}\rightarrow 4)\) clusters, performed at the B3LYP/sdd level for Gd and B3LYP/6-311++G(3df) level for F, B and Mg using the Gaussian-03 suite of programs, show that MgF3 and GdF4 with electron affinities of 6.18 and 6.85 eV, respectively, behave as superhalogens while Mg(BF4)3 and Gd(BF4)4 with electron affinities of 9.24 and 9.70 eV, respectively, behave as hyperhalogens. In addition, the magnetic moment on the Gd atom remains close to its atomic value irrespective of whether it is attached to F or BF4 moieties.