EMPIRICAL TIGHT-BINDING TOTAL ELECTRONIC-ENERGY CALCULATION FOR SINH2M (N = 1 TO 6, M = 1 TO 3) CLUSTERS

The stable structures of SinH2m (n = 1 to 6, m = 1 to 3) clusters are investigated by the total electronic energy calculation using an empirical tight-binding (ETB) method. It seems that bridged H-bond models are also possible for small Si(n)H(m) clusters

STRUCTURAL STABILITY AND ENERGETICS OF AS, SB AND BI MICROCLUSTERS - EMPIRICAL MANY-BODY POTENTIAL-ENERGY FUNCTION CALCULATION

The structural stability and energetics of As, Sb and Bi microclusters having 3-7 atoms have been investigated by using a recently developed empirical many-body potential energy function (PEF), which comprises two- and three-body atomic interactions. The PEF satisfies both bulk cohesive energy per atom and bulk structural stability exactly. It has been found that the most stable structures of As3, Sb3 and Sb4 microclusters are in linear form with D-infinity-h symmetry, Bi7 is in hexagonal pyramid form with D6v symmetry. The rest of the microclusters prefer the planar form

Adsorption of H2O on double layer stepped Si(111) surface

We have investigated possible water adsorption forms on stepped Si(111) surface. Calculations have been performed by using the empirical tight-binding method. Two types of adsorption model of water on single layer stepped Si(111) surface have been considered; one of them is the dissociative type (H, OH) and the other is the molecular type (H2O). The total electronic energy and TDOS calculations lead to a dissociative type of adsorption of water on stepped Si(111) surface excluding the molecular type. (C) 1997 Elsevier Science B.V

MOLECULAR-DYNAMICS SIMULATION OF GALLIUM MICROCLUSTERS

We have investigated the energetics and the structural stability of gallium microclusters including 3–7 atoms. A molecular-dynamics technique is employed in the simulation. The potential energy function used in the calculations includes two- and three-body interactions which are represented by Lennard-Jones and Axilrod-Teller type functions, respectively. It was found that the planar configurations are energetically more favorable for all the clusters studied

DEPENDENCE OF RESONANCE STATES ON DOPING LEVEL AND DOPING DISTRIBUTION TYPE IN GAAS GA0.75AL0.25AS SUPERLATTICE

The electronic structure of a uniformly and modulation-doped GaAs/Ga0.75Al0.25As superlattice has been investigated by a self-consistent field calculation within the effective mass approximation for three different doping concentrations. It has been found that the resonance state energies show a strong dependence on the doping level and the doping distribution type of the superlattice

STRUCTURAL STABILITY AND ENERGETICS OF SI4 ISOMERS - TOTAL ELECTRONIC-ENERGY CALCULATION

The structural stability and energetics of Si4 isomers have been investigated by using an empirical tight-binding (ETB) method. It has been found that the most stable Si4 microcluster is an exact tetrahedron with T(d) symmetry

Atomic and electronic properties of spherical silicon clusters

We have investigated the atomic and electronic properties of spherical ideal Si-N clusters (N = 5-417) using the empirical many-body potential energy function consisting of two- and three-body interactions, and by empirical tight-binding calculations, respectively. It has been found that the average interaction energy per atom decreases as the cluster size increases, and it becomes almost constant after the size N greater than or equal to 275. On the other hand, the band gap shows cluster size dependent characteristics; the band gap decreases as the cluster sire increases

Water adsorption on the stepped Si(110) surface

We have investigated the possible water adsorption forms on the stepped Si(110) surface. Calculations have been performed by using the empirical tight-binding method. Two types of adsorption model of water on a single layer stepped Si(110) surface have been considered, one of them is the dissociative type (H, OH) and the other one is the molecular type (H2O). The total electronic energy and TDOS calculations lead to a dissociative type of water adsorption on the stepped Si(110) surface excluding the molecular type as it was found on the flat Si(110) surface

MOLECULAR-DYNAMICS SIMULATION OF GOLD MICROCLUSTERS

We have investigated the energetics and the structural stability of gold microclusters containing 3–7 atoms. Molecular-dynamics techniques are employed in the simulation. The potential energy function used in the calculations includes two- and three-body interactions which are represented by Lennard-Jones- and Axilrod-Teller-type functions, respectively

Optical transitions in Si/Ge superlattices

We have performed self-consistent field calculations of the electronic structure of Si/Ge square-well superlattices within the effective-mass theory. We have computed the optical transition matrix elements involving transitions from the hole states to states in the conduction band, and we have also computed the oscillator strength matrix elements for the transitions between the states in the conduction band. (C) 1997 Elsevier Science S.A