ICOSAHEDRAL SYMMETRY AND MAGNETIC-PROPERTIES OF SMALL NICKEL METAL-CLUSTERS

The effect of the local symmetry on the magnetic properties of small N ickel clusters (up to 13 atoms) is investigated and compared with Pd a nd Rh equivalent structures. By means of self-consistent field/configu ration interaction (SCF/CI) calculations of the intermediate neglect o f differential overlap (INDO) type, the detailed geometry and multipli city of the metal structures were determined. Low multiplicities in 5- fold symmetries are found to be more stable for the 13-atom clusters a nd can be described as the result of a spin quenching that follows a J ahn-Teller distortion of the higher symmetric icosahedral structures. The association of the magnetic properties of quasicrystals to the ico sahedral symmetry is discussed.