ATOMIC AND ELECTRONIC-STRUCTURES OF PD-13 AND PT-13 CLUSTERS

The electronic structures of Pd-13 and Pt-13 clusters of cuboctahedral and icosahedral symmetries are analyzed by the self-consistent spin-p olarized density-functional scheme using the norm-conserving pseudopot ential in the linear combination of atomic orbitals method. The electr onic structure is discussed in relation to the shell structure of the giant atom. The stable atomic structure is discussed, considering the effects of the generalized gradient approximation of the exchange-corr elation potential, the spin-orbit splitting, and the-Jahn-Teller effec t. The spin-orbit coupling effect depends on the symmetry of the whole cluster. It is the largest of these effects for Pt, and it is as larg e as the spin polarization effect for Pd. The electronic structure of Pd and Pt clusters of 13 atoms is comprehended as a complex of the she ll structure and the localized Pd-4d or Pt-Sd orbitals. The Jahn-Telle r effect seems to be small to keep the shell structure. For both Pd an d Pt metals the cuboctahedron clusters are more stable and have small spin polarization, S=3 for the Pd cluster and S=4 for the Pt cluster. [S0163-1829(98)02527-2].