Phase diagram of H2 adsorbed on graphene

The phase diagram of the first layer of H2 adsorbed on top of a single graphene sheet has been calculated by means of a series of diffusion Monte Carlo simulations. We have found that, as in the case of H4e, the ground state of molecular hydrogen is a 3¿×3¿ commensurate structure, followed, upon a pressure increase, by an incommensurate triangular solid. A striped phase of intermediate density was also considered and found lying on top of the equilibrium curve separating both commensurate and incommensurate solids.Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y NaturalesVersión del edito