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

Gupte, Girish R.; Prasad, R.

doi:10.1142/s0217979298000880

Cited by 20 publications

(9 citation statements)

References 27 publications

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“…[18] clearly demonstrate that our MGAC/CPMD approach is able to find new, previously unknown, structures with significant lower energy than those previously reported by other authors [21][22][23][24][25][26]. The results in Ref .…”

Section: Dft Global Optimizationssupporting

confidence: 71%

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

et al. 2005

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The study of the structure and physical properties of atomic clusters is an extremely active area of research due to their importance, both in fundamental science and in applied technology. For medium size atomic clusters most of the structures reported today have been obtained by local optimizations of plausible structures using DFT (Density Functional Theory) methods and/or by global optimizations in which much more approximate methods are used to calculate the cluster's energetics. Our previous work shows that these approaches can not be reliably used to study atomic cluster structures and that approaches based on global optimization schemes are needed. In this paper, we report the implementation and application of a parallel Genetic Algorithm (GA) to predict the structure of medium size atomic clusters.

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Section: Dft Global Optimizationssupporting

confidence: 71%

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

et al. 2005

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“…9,10 Most of the theoretical studies on silicon hydrogen clusters have been carried out on SiH m (m = 1, 4) 2,11 or disilane. 3,4,11 Onida and Andreoni 5 have considered hydrogen passivated crystal fragments such as Si 5 H 12 , Si 6 H 12 , Si 10 H 16 etc. In this paper we focus on small Si n H clusters (n = 3, 10).…”

Section: Introductionmentioning

confidence: 99%

“…The work on Si n H m clusters (n = 1, 2 and m = 1-6) has been already reported elsewhere. 11 Our calculations are carried out using the nonorthogonal tight-binding molecular dynamics (NTBMD) of Menon and Subbaswamy. 12 As far as the nonorthogonal tight-binding method is concerned, Singh et al 13 were probably the first ones to apply it to silicon clusters.…”

Section: Introductionmentioning

confidence: 99%

“…The use of these parameters yielded ground state geometries and frequencies of normal modes of Si n H m clusters (n = 1, 2 and m = 1-6) in good agreement with experimental and ab initio calculations. 11 Using these parameters and computationally efficient NTBMD scheme, it is now possible to simulate much bigger clusters of hydrogen and silicon.…”

Section: Introductionmentioning

confidence: 99%

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Geometries and Vibrational Spectra of Small Hydrogenated Silicon Clusters

Gupte

Prasad

1998

Int. J. Mod. Phys. B

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We report a systematic study of ground state structures, vibrational spectra, cohesive energies and HOMO-LUMO gaps of small SinH 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 Sin 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 SinH 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, Si 3 H and Si 5 H will be more stable and Si 4 H, Si 6 H, Si 7 H, Si 9 H and Si 10 H will be less stable clusters.

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“…The optimized geometries of the reactants, major transition states, and products calculated at the B3LYP/6–311++G(3df,2p) level of theory. The values in brackets are the experimental values . Lengths are in angstrom (Ǻ), and angles are in degrees ( °).…”

Section: Resultsmentioning

confidence: 99%

Ab Initio Chemical Kinetics for SiH_xReactions with Si₂H_y(x= 1,2,3,4;y= 6,5,4,3;x+y= 7) under a-Si:H CVD Condition

Nguyen

Lin

2017

Int. J. Chem. Kinet.

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Gas‐phase reactions of SiHx with Si2Hy (x = 1,2,3,4; y = 6,5,4,3) species, respectively, which may coexist under chemical vapor deposition (CVD) conditions, have been investigated by means of ab initio molecular orbital and statistical theory calculations. Potential energy surface (PES) predicted at the CCSD(T)/CBS//B3LYP/6–311++G(3df,2p) level shows that these reactions take place primarily via trisilany radicals, n‐Si3H7 and i‐Si3H7. For example, SiH2 can associate with Si2H5 producing n‐H2SiSiH2SiH3 exothermically by 55.8 kcal/mol; SiH3 can undergo addition to H2SiSiH2 to produce n‐Si3H7 or associate with H3SiSiH barrierlessly forming i‐Si3H7; whereas SiH can insert into one of the Si─H bonds of Si2H6 to give excited n‐Si3H7. Similarly, H2SiSiH and SiSiH3 can undergo insertion reactions with SiH4 producing n/i‐Si3H7 intermediates, respectively, to be followed by fragmentation to various smaller species. These processes are fully depicted in the complete PES. The predicted heats of formation of various species agree well with available thermochemical data. The rate constants and product branching ratios for the low‐energy channel products have been calculated for the temperature range 300–1000 K by variational RRKM (Rice–Ramsperger–Kassel–Macus) theory with Eckart tunneling corrections. The results may be employed for realistic kinetic modeling of the plasma‐enhanced chemical vapor deposition growth of a‐Si:H thin films under practical conditions.

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

Cited by 20 publications

References 27 publications

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

Geometries and Vibrational Spectra of Small Hydrogenated Silicon Clusters

Ab Initio Chemical Kinetics for SiH_xReactions with Si₂H_y(x= 1,2,3,4;y= 6,5,4,3;x+y= 7) under a-Si:H CVD Condition

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

Cited by 20 publications

References 27 publications

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms

Geometries and Vibrational Spectra of Small Hydrogenated Silicon Clusters

Ab Initio Chemical Kinetics for SiHxReactions with Si2Hy(x= 1,2,3,4;y= 6,5,4,3;x+y= 7) under a-Si:H CVD Condition

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Product

Resources

About

Ab Initio Chemical Kinetics for SiH_xReactions with Si₂H_y(x= 1,2,3,4;y= 6,5,4,3;x+y= 7) under a-Si:H CVD Condition