Geometrical And Electronic Properties Of Small Clusters For Nickel, Palladium And Platinum

The nanometer material and technology is the most alive subject branch, with very abundant research connotation in the nanometer of scientific and technological fields, and nanometer is occupying central position in research application of the whole new material. The atomic cluster is one of the elementary cell which forms nanometer body, membrane, multilevel membrane and nanometer structure, so the theoretical research for ground-state structures, energy level distribution and electronic properties of its is one of the important subject in the design of micro structure of new material, and has great signification in"custom-made"new material with specific performance.In this paper, the molecular structure of small clusters for nickel, palladium and platinum have been calculate by use of the density function theory (DFT) B3LYP method with relativistic effective core potential (RECP) and Gaussian98W program. The shaping regularities of small Nin, Pdn, and Ptn (n = 2-6) clusters is analyzed based on structures and vibration spectrum. Finally, the energy level distribution, HOMO—LUMO gaps, electron affinities (EA), ionization potentials (IP) and chemical activity are discussed.The ground-state structures of the nickel micro-clusters are planar, it is similar to alkali metal cluster, the change of 2D→3D is occurred from Ni4. HOMO and LUMO energies of Nin(n = 2-6) cluster are all negative, which shows that the cluster is difficult to lose electron. The HLGs of Nin(n = 2-6) cluster is big, and the chemical activation is weaker.The results for the study of the Pdn(n=2-6) clusters indicate that the ground electronic state is 3Σu+ for Pd2. The ground state configuration of Pd3 cluster is an isosceles triangle with C2v symmetry in the 3B2 electronic state. Both clusters, Pd5 and Pd6, are of C2v symmetry, and the ground electronic state is 1A1 and 3B2, respectively. Due to the Jahn-Teller effect, the present calculations for Pd4 obtain a noncompact tetrahedron ground state with Cs symmetry in the 3A″electronic state.The results of the Ptn(n=2-6) clusters show that the ground electronic state is 3Σu+ for Pt2. The ground state configuration of Pt3 cluster is an isosceles triangle with Cs symmetry in the 1A′electronic state. Both clusters, Pt4 and Pt6, are of C2v symmetry, and the ground electronic state is 3B2 and 5A2, respectively. The present calculations for Pt5 obtain a pyramid ground state form with C4v symmetry in the 7B1 electronic state.