  We present linear ensembles of dangling bond chains on a hydrogen terminated
Si(100) surface, patterned in the closest spaced arrangement allowed by the
surface lattice. Local density of states maps over a range of voltages
extending spatially over the close-coupled entities reveal a rich energetic and
spatial variation of electronic states. These artificial molecules exhibit
collective electronic states resulting from covalent interaction of the
constituent atoms. A pronounced electrostatic perturbation of dangling bond
chain structure is induced by close placement of a negatively dangling bond.
The electronic changes so induced are entirely removed, paradoxically, by
addition of a second dangling bond.
