Quasilattice-conserved optimization of the atomic structure of decagonal Al-Co-Ni quasicrystals

Abstract

The detailed atomic structure of quasicrystals has been an open question for decades. Here, we present a quasilattice-conserved optimization method (quasiOPT), with particular quasiperiodic boundary conditions. As the atomic coordinates described by basic cells and quasilattices, we are able to maintain the self-similarity characteristics of qusicrystals with the atomic structure of the boundary region updated timely following the relaxing region. Exemplified with the study of decagonal Al-Co-Ni (d-Al-Co-Ni), we propose a more stable atomic structure model based on Penrose quasilattice and our quasiOPT simulations. In particular, "rectangle-triangle" rules are suggested for the local atomic structures of d-Al-Co-Ni quasicrystals.