Hund's rule in metal clusters:: Prediction of high magnetic moment state of Al12Cu from first-principles calculations -: art. no. 115405

Using ab initio pseudopotential plane wave method and generalized gradient approximation for the exchange and correlation energy, we report the finding of high spin ground state of Ali,Cu cluster in accordance with the Hund's rule of maximum spin at half-filling. It has perfect icosahedral symmetry and a magnetic moment of 3 mu (B), forming an open shell superatom. Further studies of its interaction with an At atom have led to an electronically closed shell magic cluster with 1.68 eV highest occupied-lowest unoccupied molecular orbital (HOMO-LUMO) gap such that the added At atom is incorporated within the cage around the Cu atom.