First-principles electronic structure studies for the cluster modeled Si/Si(111) chemisorption system

Ab initio density functional theory (DFT) methods have been employed to inv estigate the electronic structure of atomic clusters representing the T-4 a nd H-3 adatom bonding configurations of the Si(111)root 3x root 3R30 degree s -Si reconstructed surface. The nature of the bending between the Si adato m and its nearest neighbor atoms on the Si(111) surface is discussed by ana lyzing the density of states (DOS), projected DOS, charge distributions and the molecular orbital overlap population (MOOP). The results provide an ex planation for the difference in stability between the T-4 and H-3 configura tions. (C) 2001 American Institute of Physics.