scholarly journals Electronic counting rules for the stability of metal-silicon clusters

2006 ◽  
Vol 74 (3) ◽  
Author(s):  
J. Ulises Reveles ◽  
S. N. Khanna
Keyword(s):  
Silicon Clusters ◽  
Counting Rules ◽  
The Stability ◽  
Electronic Counting

A DFT Study of Geometric Structure and Stability of Iron-Silicon Clusters

2014 ◽  
Vol 1048 ◽  
pp. 369-372
Author(s):  
Shuai Qin Yu ◽  
Hong Nan Ye
Keyword(s):  
Density Functional Theory ◽  
Geometric Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Surface Site ◽  
Silicon Clusters ◽  
Lumo Energy ◽  
Functional Theory ◽  
The Stability ◽  
Homo Lumo

Geometric structures of Fe6-xSix(x=1-5) clusters have been systematically studied at the BPW91 level by density-functional theory (DFT). Calculated results show that the Fe atoms of the lowest-energy structures of Fe6-xSix clusters tend to go together, and Si atoms tend to occupy surface site bonding with iron atoms as many as possible. Further, we analyze the stability of the lowest-energy structures of Fe6-xSix clusters, and the corresponding results of the HOMO, LUMO as well as the HOMO-LUMO energy gap show that the Fe5Si and Fe4Si2 clusters have special stability.

On the Use of Bond-Counting Rules in Predicting the Stability of C12B6N6 Fullerene

2008 ◽  
Vol 112 (40) ◽  
pp. 15691-15696 ◽  
Author(s):  
X. F. Fan ◽  
Zexuan Zhu ◽  
Z. X. Shen ◽  
Jer-Lai Kuo
Keyword(s):  
Counting Rules ◽  
The Stability

Application of Electronic Counting Rules for Ligand-Protected Gold Nanoclusters

2018 ◽  
Vol 51 (11) ◽  
pp. 2739-2747 ◽  
Author(s):  
Wen Wu Xu ◽  
Xiao Cheng Zeng ◽  
Yi Gao
Keyword(s):  
Gold Nanoclusters ◽  
Counting Rules ◽  
Electronic Counting

scholarly journals FIELD EVAPORATION OF GROUNDED ARSENIC DOPED SILICON CLUSTERS

2015 ◽  
Vol 22 (06) ◽  
pp. 1550069
Author(s):  
ZEXIANG DENG ◽  
JUNCONG SHE ◽  
ZHIBING LI ◽  
WEILIANG WANG ◽  
QIANG CHEN
Keyword(s):  
Electric Fields ◽  
Density Functional ◽  
Binding Energies ◽  
Field Evaporation ◽  
Silicon Clusters ◽  
Functional Theory ◽  
As Doping ◽  
Doped Silicon ◽  
The Difference ◽  
The Stability

We have investigated the field evaporation of grounded arsenic (As) doped silicon (Si) clusters composed of 52 atoms with density functional theory (DFT) to mimic Si nano structures of hundreds of nanometers long standing on a substrate. Six cluster structures with different As doping concentrations and dopant locations are studied. The critical evaporation electric fields are found to be lower for clusters with higher doping concentrations and doping sites closer to the surface. We attribute the difference to the difference in binding energies corresponding to the different As-doping concentrations and to the doping locations. Our theoretical study could shed light on the stability of nano apexes under high electric field.

Geometries and Vibrational Spectra of Small Hydrogenated Silicon Clusters

1998 ◽  
Vol 12 (16n17) ◽  
pp. 1737-1750 ◽  
Author(s):  
Girish R. Gupte ◽  
R. Prasad
Keyword(s):  
Vibrational Spectra ◽  
Ground State ◽  
Tight Binding ◽  
Silicon Clusters ◽  
Hydrogenated Silicon ◽  
First Case ◽  
Stable Clusters ◽  
Ground State Structures ◽  
The Stability ◽  
Cohesive Energies

We report a systematic study of ground state structures, vibrational spectra, cohesive energies and HOMO-LUMO gaps of small Si n H clusters (n=3, 10) based on the nonorthogonal tight-binding molecular dynamics scheme. The ground state structures have been obtained by using simulated annealing. In particular, we focus on how the addition of a hydrogen atom affects the ground state geometry and the stability of a Si n cluster. We find that hydrogen either enters into the surface of the cluster or occupies a position outside the cluster. In the first case, it drastically distorts the cluster, while in the latter, there is very little distortion. We find that in some cases Si n H cluster has some resemblance with Si n+1 cluster. We also find that hydrogen can form bonds with more than one silicon atom. Our calculation indicates that SiH, Si3H and Si5H will be more stable and Si4H , Si6H , Si7H , Si9H and Si10H will be less stable clusters.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Sign in / Sign up

Export Citation Format

Share Document