Figure 5

Determining torsional and self-adhesion energy barriers. (a) Torsion: A simple five-atom carbyne system with an imposed curvature (κ = 0.016 to 0.395 Å^-1, inset κ = 0.2 Å^-1) is subject to incremental twist while tracking the potential energy. The cyclical energy change due to a 180° twist increases with initial curvature as shown, defining the energy barrier (indicated by arrows) to untwist a carbyne chain in the looped configuration. (b) Adhesion: Three short six-atom carbyne chains (to reflect a three-loop adhesion case) were brought into close proximity over time to determine the interchain adhesion energy barrier, defined as the depth of the potential energy well (indicated by arrows).