  We study the physics of Dirac fermions in a gapped graphene monolayer
containing two Coulomb impurities. For the case of equal impurity charges, we
discuss the ground-state energy using the linear combination of atomic orbitals
(LCAO) approach. For opposite charges of the Coulomb centers, an electric
dipole potential results at large distances. We provide a nonperturbative
analysis of the corresponding low-energy scattering problem.
