scholarly journals Effect of hydrogen on ground-state structures of small silicon clusters

2001 ◽  
Vol 64 (20) ◽  
Author(s):  
D. Balamurugan ◽  
R. Prasad
Keyword(s):  
Ground State ◽  
Silicon Clusters ◽  
Ground State Structures

Ground State Geometries and Vibrational Spectra of Small Hydrogenated Silicon Clusters using Nonorthogonal Tight-Binding Molecular Dynamics

1998 ◽  
Vol 12 (15) ◽  
pp. 1607-1622 ◽  
Author(s):  
Girish R. Gupte ◽  
R. Prasad
Keyword(s):  
Molecular Dynamics ◽  
Vibrational Spectra ◽  
Ground State ◽  
Tight Binding ◽  
Normal Modes ◽  
Silicon Clusters ◽  
Hydrogenated Silicon ◽  
Ground State Structures ◽  
Cohesive Energies ◽  
Homo Lumo

We report a systematic study of ground state structures, vibrational spectra cohesive energies and HOMO-LUMO gaps of small Si n H m clusters (n=1, 2 and m=1–6) and their deuterated derivatives based on the nonorthogonal tight-binding molecular dynamics scheme. The ground state structures have been obtained by using simulated annealing. The bond lengths, bond angles and the frequencies of normal modes are found to be in good agreement with available experimental data and ab initio calculations. Our calculation of cohesive energies indicate SiH 2 to be more stable than SiH 3 or SiH and Si 2 H 4, more stable than Si 2 H 3 or Si 2 H 5.

DENSITY FUNCTIONAL THEORY STUDIES OF CHARGED, COPPER-DOPED, SMALL SILICON CLUSTERS, ${\rm CuSi}_{n}^{+}/{\rm CuSi}_{n}^{-}$ (n = 1–7)

2012 ◽  
Vol 11 (01) ◽  
pp. 185-196 ◽  
Author(s):  
GUOLIANG LI ◽  
WENLIANG MA ◽  
AIMEI GAO ◽  
HONGYU CHEN ◽  
DAVID FINLOW ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Binding Energies ◽  
Silicon Clusters ◽  
Functional Theory ◽  
Molecular Orbit ◽  
Lowest Unoccupied Molecular Orbital ◽  
Ground State Structures

The structures and stabilities of charged, copper-doped, small silicon clusters [Formula: see text] (n = 1–7) have been systematically investigated using the density functional theory method at the B3LYP/6-311+G* level. For comparison, the geometries of neutral CuSi n clusters were also optimized at the same level, although most of them have been reported previously [see Xiao CY, Abraham A, Quinn R, Hagelberg F, Comparative study on the interaction of scandium and copper atoms with small silicon clusters, J Phys Chem A106:11380, 2002; Liu X, Zhao GF, Guo LJ, Wang XW, Zhang J, Jing Q, Luo YH, First-principle studies of the geometries and electronic properties of Cu m Si n (2 ≤ m + n ≤ 7) clusters, Chin Phys16:3359, 2007]. Our results for the ground state structures of neutral CuSi n clusters agree well with those of Liu et al. and Xiao et al. except for CuSi3 and CuSi7 . Removing or adding an electron greatly changes some ground state structures, i.e. for [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text]; others are almost unchanged, e.g. [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. The ground states of ionic [Formula: see text] are all singlet, except for the smaller CuSi- and [Formula: see text]. Based on the optimized geometries, various energetic properties, including binding energies, second-order difference energies, the highest occupied molecular orbit and the lowest unoccupied molecular orbital (HOMO–LUMO) energy gaps, ionization potential and electron affinities, were calculated for the most stable isomers of [Formula: see text]. All the results indicate that anionic [Formula: see text] and cationic [Formula: see text] clusters are relatively stable. The higher stability of the latter has been confirmed by Beck's observations.

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.

STRUCTURE, STABILITY, AND ELECTRONIC PROPERTIES OF LARGE FULLERENES

1993 ◽  
Vol 07 (26) ◽  
pp. 4305-4329 ◽  
Author(s):  
C.Z. WANG ◽  
B.L. ZHANG ◽  
K.M. HO ◽  
X.Q. WANG
Keyword(s):  
Total Energy ◽  
Electronic Properties ◽  
Ground State ◽  
Relative Stability ◽  
Chemical Reactivity ◽  
Structure Stability ◽  
Quantum Mechanical ◽  
Efficient Scheme ◽  
Ground State Structures ◽  
Fullerene Clusters

The recent development in understanding the structures, relative stability, and electronic properties of large fullerenes is reviewed. We describe an efficient scheme to generate the ground-state networks for fullerene clusters. Combining this scheme with quantum-mechanical total-energy calculations, the ground-state structures of fullerenes ranging from C 20 to C 100 have been studied. Fullerenes of sizes 60, 70, and 84 are found to be energetically more stable than their neighbors. In addition to the energies, the fragmentation stability and the chemical reactivity of the clusters are shown to be important in determining the abundance of fullerene isomers.

Exploring the Real Ground-State Structures of Molybdenum Dinitride

2016 ◽  
Vol 120 (20) ◽  
pp. 11060-11067 ◽  
Author(s):  
Shuyin Yu ◽  
Bowen Huang ◽  
Xiaojing Jia ◽  
Qingfeng Zeng ◽  
Artem R. Oganov ◽  
...  
Keyword(s):  
Ground State ◽  
The Real ◽  
Ground State Structures

A Density Functional Study of Structures and Vibrations of Ta3O and Ta3O−

2005 ◽  
Vol 1 (4) ◽  
pp. 164-171 ◽  
Author(s):  
Patrizia Calaminici ◽  
Roberto Flores–Moreno ◽  
Andreas M. Köster
Keyword(s):  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Equilibrium Structure ◽  
Negative Ion ◽  
Functional Study ◽  
Experimental Prediction ◽  
Extra Electron ◽  
Ground State Structures ◽  
Good Agreement

Density functional calculations of neutral and anionic tantalum trimer monoxide are presented. The calculations were performed employing scalar quasi–relativistic effective core potentials. Different isomers of Ta3O and Ta3O- were studied in order to determinethe ground state structures. For both systems a planar C2vstructure with an edge-boundoxygen atom was found as ground state. Equilibrium structure parameters, harmonic frequencies, adiabatic electron affinity and Kohn-Sham orbital diagrams are reported. The calculated values are in good agreement with the available experimental data obtained from negative ion photoelectron spectroscopy. The correlation diagram between the neutral and anionic Ta3O shows that, in agreement with the experimental prediction, the extra electron in the anionic system occupies a nonbonding orbital.

STABLE STRUCTURES, ELECTRIC AND MAGNETIC PROPERTIES OF NANOPARTICLES COn(n = 1-6) CLUSTERS: FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362007
Author(s):  
JUN LIU ◽  
SHENG-BIAO TAN ◽  
HUI-NING DONG
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
First Principles ◽  
Lower Energy ◽  
Magnetic Moments ◽  
Molecular Orbitals ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Ground State Structures ◽  
Stable Structures

The ground state geometric structures of the nanoparticles or clusters CO n(n = 1-6) were given based on the first-principles calculations. Then the magnetic properties of the clusters CO n(n = 1-6) and ( CO n)-2(n = 1-6) were calculated in system. Results show that their ground state structures are closely related to the numbers of O-ions. These clusters have no magnetic moments and half-metallicity if they are electroneutral. However, they have magnetic moments if they have positive or negative charges. The total magnetic moments of the clusters ( CO n)-2(n = 1-6, but n≠3) are all 2.0000 μB, and all their ions have contributions to the total magnetic moments. The main reason is that the molecular orbitals with lower energy filled with paired electrons and the molecular orbitals with higher energy are occupied by two electrons in parallel.

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