Multiple Silicon Atom Artificial Molecules
  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. 
John A. Wood, Mohammad Rashidi, Mohammad Koleini, Jason L. Pitters and   Robert A. Wolkow
cond-mat.mes-hall