Simulation of the Au(111)-(22×√3) surface reconstruction
The (223) reconstruction of the Au(111) surface is modeled using a priori density-functional theory simulations involving use of Born-Oppenheimer molecular dynamics and simulated annealing procedures. The reconstruction is exothermic by 0.43 eV per surface cell. Domains with surface atoms locating above fcc, hcp, and bridge sites of the second layer are produced, in quantitative agreement with experimental observations. While the reconstruction occurs to reduce the surface stresses created by cleavage of the bulk metal by minimizing the surface gold-gold interatomic separations, excess contraction appears associated with the bridge domains, causing them to stand out and form ridges above the surface. However, the chemical activity of the surface is reduced as the local surface density increases, making the fcc domain the most active part while the hcp domain and bridge ridges are less active.
Physical Review B
Surfaces and Structural Properties of Condensed Matter