Figure 1

Snapshots at different stages of the pulling process [31] at four elevations of the terminal carbon atom ${\mathrm{C}}^{\star }$ of ethylthiolate relative to its relaxed initial position (a) 0.0 Å, (b) 5.0 Å, (c) 10.6 Å (d) 11.0 Å. For clarity, parts of the adjacent periodic images are displayed together with the simulation cell and the darkened gold atoms were fixed at their optimized bulk positions. The arrows indicate the pulling direction and the insets magnify the alterations of the contact junction close to the surface. There, gold atoms with a coordination number reduced to half their initial value are depicted by small spheres, which visualizes the extraction process from the surface.Reuse & Permissions

Figure 2

Observables as a function of the elevation of the terminal carbon atom ${\mathrm{C}}^{\mathrm{\star }}$ of ethylthiolate relative to its relaxed initial position. Panel (a): Sulfur-gold distances of the three closest neighbors to which the sulfur was coordinated initially; see inset in Fig. 1a. Inset: Time-resolved representation of the dynamics of the bond distances S-Au1 and S-Au2 in the shaded regime. Panel (b): Evolution of the forces in the pulling direction ($⟨111⟩$) and orthogonal to the pulling direction ($⟨11\overline{2}⟩$, $⟨1\overline{1}0⟩$); the sign of the pulling force is chosen according to the experimental convention. Panel (c): Mean absolute displacement of the first and the second layer of gold atoms relative to their initial positions. The plateaus I–IV indicate stable stages of the second layer configuration during the pulling process and correspond to the formation of distinct surface species. Stage I, transition from S bound to three Au atoms to two Au atoms forming a “dimeric Au1-Au2 unit.” Stage II, dimeric unit within surface terrace and thiolate directly above it. Stage III, dimeric unit above surface terrace with a defect Au atom located directly below the dimer. Stage IV, formation and extraction of a thiolate-terminated gold nanowire.Reuse & Permissions

Figure 3

Orthogonal projection on the ($1\overline{1}0$) plane, which visualizes the trajectories of the rupture simulation before the wire breaks. The atomic coordinates of the unrelaxed bulk terminated (221) surface without molecule chemisorbed is shown for reasons of clarity (large gray circles). The pathway of those gold atoms that form the wire are marked blue. That of Au1 (which remains directly bound to the sulfur) is highlighted with small blue circles showing its position every 100 configurations. Inset: Crystal lattice vectors of the bulk terminated (221) surface.Reuse & Permissions