▎ 摘　　要

We suggest theoretically the existence of a stoichiometric derivative of graphene, a two-dimensional analog of polyvinylidene fluoride, with fluorine and hydrogen atoms alternately attached to carbon atoms in a chairlike configuration. Analyzing the different possible decorations of H and F of graphene, we find that all are unstable but one. This low-energy structure has a wide band gap and an elastic strength comparable to that of pristine graphene. One other structure is shown to become stable under compressive stress.