In this paper, we present the results of our first-principles quantum mechanical studies of the electronic structure, geometry, and linear and nonlinear optical (NLO) properties of tetrahedral GamNm (m=1, 4, 7, 17) atomic clusters. Our calculated results suggest that the linear and NLO properties both exhibit a strong dependence upon cluster size and shape (geometry). However, the sizeand the g...

Starting from the gas phase, small clusters can be produced and deposited with huge flexibility with regard to composition, materials choice and cluster size. Despite many advances in experimental characterization, a detailed morphology of such clusters is still lacking. Here we present an atomic scale observation as well as the dynamical behaviour of ultrasmall germanium clusters. Using quanti...

Precipitation kinetics of Al3Zr and Al3Sc in aluminum supersaturated solid solutions is studied using cluster dynamics, a mesoscopic modeling technique which describes the various stages of homogeneous precipitation by a single set of rate equations. The only parameters needed are the interface free energy and the diffusion coefficient which are deduced from an atomic model previously developed...

Kinetic energies of Tan þ and Nbn þ ions (1 n 10) sputtered from pure Ta and Nb targets by 6 keV per atom Au , Au2 and Au3 primary ions have been compared after energy spectra of these ions were recalibrated using a newly developed data processing algorithm. Most probable and mean energies were determined for the sputtered ions, and their energy spectra were converted into distributions over in...

-The structural and thermodynamic properties of microclusters in two and three dimensions have been investigated by means of the molecular dynamics technique. This technique in principle produces the atomic configuration of lowest free energy for any given cluster size. The caloric equation of state for the different microclusters were calculated using a truncated Lennard-Jones pair potential. ...

Anionic water clusters have long been studied to infer properties of the bulk hydrated electron. In particular, the question of whether the excess electron is on the surface of the cluster or in the interior of the clusters has been the subject of much speculation. The successes of solid-state physics are built on exploiting the regularity of atomic arrangements in crystal. Describing the cryst...

-We have investigated the influence of charge on the ground state structures for small Sin (n=5-10) clusters by using the full-potential linear muffin-tin orbital molecular-dynamics (FP-LMTO-MD) method. Addition or removal of one or two electrons does not change the geometrical configurations of the small Sin (n=5-10) clusters even though they undergo some structural distortion. But the structu...

Surface based mass spectrometric approaches fill an important niche in the mass analysis portfolio of tools. The particular niche depends on both the underlying physics and chemistry of molecule ejection as well as experimental characteristics. In this article, we use molecular dynamics computer simulations to elucidate the fundamental processes giving rise to ejection of organic molecules in a...

Using neon and its dimer as a specific example, it is shown that excited Auger decay channels that are electronically stable in the isolated monomer can relax in a cluster by electron emission. The decay mechanism, leading to the formation of a tricationic cluster, is based on an efficient energy-transfer process from the excited, dicationic monomer to a neighbor. The decay is ultrafast and exp...

The atomic environments of two chalcogenide glasses, with compositions GeSe4In10 and GeSe4In15, were studied via Reverse Monte Carlo and Density Functional Theory. Indium content demoted Ge–Se bonding in favor of Se-In while the contribution of Se–Se in the first coordination shell order was faint. Upon transition to the richer In glass, there was formation of rich Ge-centered clusters at radia...