First principles study of the electronic and geometric structure of Cu(532)

TL;DR

This study uses density functional theory to analyze the atomic and electronic structure of the Cu(532) surface, revealing significant relaxations, a dispersionless surface state, and charge distribution details.

Contribution

It provides the first detailed first-principles analysis of the Cu(532) surface, highlighting relaxation patterns and electronic states with high accuracy.

Findings

25% outward expansion of interlayer separation d12

Presence of a dispersionless surface state

Charge density shows bonding around kink atoms

Abstract

Using density functional theory with the generalized gradient approximation and ultra-soft pseudo-potentials, we have calculated structural relaxations of the Cu(532) surface which contains steps and kinks. We find the relaxation pattern to oscillate dramatically for atoms in the first 10 layers before decaying rapidly in the bulk. The most striking feature is an outward expansion of the relative interlayer separation $\mathbf{d}_{12}$ of 25%. We also find serious discrepancies with relaxation pattern and relaxation amplitudes calculated using embedded atom method potentials that may reflect the limitation of these potentials to accurately describe systems with complex geometries. Full potential calculations reveal a dispersionless surface state along a high symmetry direction in the surface Brillouin zone. Valence charge density along several planes show access of charge around kink atom and the nature of bonding with other (532) atoms.