Structure and magic numbers of large Lennard-Jones quasicrystals and crystals

Abstract

As a simulation of large cluster molecular dynamics calculations are performed with the Lennard-Jones potential and initial multilayer icosahedra (mli), multilayer (mlc) or stacked cuboctahedra or hexagonal close packe spheres (hcp). Final ratios of potential to kinetic energies are about -108. Cohesive (volume) and surface energies per particle are extracted for particle numbers up to N=6525 and compared to the energies of scaled mli quasicrystals and of spherical scaled hcp, fcc, bcc crystals with N up to 36000. It is shown that relaxed mli are the dominant structures for N22000. The volume energy of infinite hcp matter is lowest with fcc and mlc being only slightly higher, followed by hexakaiicosahedra, decahedral pentakaitetrakontahedra, and mli and bcc being much higher. The surface energy of mli is smallest. The same magic numbers obtain with other short range Mie potentials.