Roadmap for the Synthesis of Exotic 2D Metastable Carbon using Topologically Assembled Precursors

Metastable structures of matter often possess properties superior to those of their ground state. A case in point is diamond vs. graphite. Yet, many predicted metastable structures are dismissed as hard-to-realize in practice as their basins of attraction are either too shallow or too narrow or both. There is no available theoretical approach that can deliberately enhance the realizability of these structures and directly guide their experimental synthesis. Here, we introduce a new approach to create potential energy surfaces in which the volumes of the basin of attraction of targeted metastable structures are increased by design, while simultaneously suppressing the accessibility of the ground state as well as other isomers.This approach is based on topologically assembled precursors, followed by density functional theory relaxations,and is applied to realize high-energy carbon allotropes such as penta-graphene comprised entirely of pentagon rings, O-graphene comprised of five- and eight-membered rings and R-graphene comprised of four-, six- and eight-membered rings.