▎ 摘　　要

We show that a dilute ensemble of epoxy-bonded adatoms on graphene has a tendency to form a spatially correlated state accompanied by a gap in graphene's electron spectrum. This effect emerges from the electron-mediated interaction between adatoms with a peculiar 1/r(3) distance dependence. The partial ordering transition is described by a random bond three-state Potts model.