title: Determination of structural transitions of atomic clusters from local and global bond orientational order parameters.
abstract: Designing an effective order parameter for the identification of geometries in atomic clusters is an important step toward understanding the structural transitions occurring in these systems. We propose a method that simultaneously utilizes the local and global bond orientational order parameters for structural transitions. When applied to Lennard-Jones clusters at finite temperature over the size range 30< or =N< or =146, this method identified all the major geometries: icosahedra with Mackay overlayers, icosahedra with anti-Mackay overlayers, decahedra, octahedra, and tetrahedra. From the distributions of these geometries as a function of temperatures on clusters containing 38, 75, and 98 atoms, we are able to interpret all transition types without ambiguity.
authors.affiliation: Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada. lzhan@sciborg.uwaterloo.ca
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhan
authors.forename: Jeff Z Y
authors.initials: JZ
authors.lastname: Chen
authors.forename: Wing-Ki
authors.initials: WK
authors.lastname: Liu