Electronic structures of the negative ions Si−2 –Si−10: Electron affinities of small silicon clusters

Raghavachari, Krishnan; Rohlfing, Celeste McMichael

doi:10.1063/1.459738

Cited by 185 publications

(109 citation statements)

References 78 publications

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“…The tetracapped tetrahedron (C 3v , (8c) in Fig. 1) and the capped pentagonal bipyramid (C s ) are the ground state structures of Si 8 -and Si 8 + , respectively [21][22][23]. Using FP-LMTO-MD method, we have investigated many structures of the ionic Si 8 cluster, including all the structures reported before.…”

Section: Resultsmentioning

confidence: 98%

“…Some theoretical calculations on the charged Si 2-10 clusters have been also done but not completed [3,21,22]. The ground state structures for the charged Si clusters are generally similar to those of their corresponding neutral clusters.…”

Section: Introductionmentioning

confidence: 93%

“…The ground state structures for Si 8 -and Si 8 + are entirely dissimilar: C 1 /C s capped pentagonal bipyramid and C 2v (or C 3v ) tetracapped tetrahedron, respectively [23]. Negative Si 9 -cluster has a ground state structure of distorted tricapped trigonal prim (C s ) [21,24], whereas cationic Si 9 + cluster has a C 2v capped stacked rhombi structure [22]. Both anionic and cationic Si 10 clusters have a ground state structure of tetracapped trigonal prism (C 3v ).…”

Section: Introductionmentioning

confidence: 98%

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Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n

Cao

Zhou

2003

Physica Status Solidi (b)

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PACS 61.46.+w, 71.15.Pd, 73.22.Dj Using full-potential linear-muffin-tin-orbital molecular-dynamics (FP-LMTO-MD) method, we have studied the geometric and electronic structures of ionic Si 2-10 clusters. The structures we obtained include not only all the most stable structures reported previously, but also some new structures. Our calculations show that the ground state structure of negative Si 8 -cluster ion is a new structure with C 2v , which is different from that reported before. In addition, we have also found that the ground state structure of positive Si + 10 cluster ion is a tricapped pentagonal bipyramid with C s symmetry, which has been not reported previously. As for their electronic structures, these charged silicon clusters show 0.5 -2.5 eV of energy gaps between the lowest unoccupied energy level and the highest occupied energy level. The gaps for cationic silicon clusters are closer to those of their corresponding neutral clusters, but many of the gaps for the anionic clusters are not.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n

Cao

Zhou

2003

Physica Status Solidi (b)

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“…After having performed the DMHM with Quickstep using a relatively small Gaussian basis set and the local density approximation (LDA), we have calculated accurate final energies and zero-point energies with the CPMD program [22] using the PBE functional [23], a high accuracy pseudo-potential [24], large super-cells (24Å) and a sufficient plane wave cutoff (28 Rydberg). The results for Si 16a , Si 18a and Si 19a as compared to Si 16 , Si 18 and Si 19 are presented in Table I. The low-lying isomer Si 16b is virtually isoenergetic with the structure Si 16 .…”

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confidence: 90%

Global Minimum Determination of the Born-Oppenheimer Surface within Density Functional Theory

2005

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We present a novel method, which we shall refer to as the dual minima hopping method (DMHM), that allows us to find the global minimum of the potential energy surface (PES) within density functional theory (DFT) for systems where a fast but less accurate calculation of the PES is possible. This method can rapidly find the ground state configuration of clusters and other complex systems with present day computer power by performing a systematic search. We apply the new method to silicon clusters. Even though these systems have already been extensively studied by other methods, we find new configurations for Si16, Si18 and Si19 that are lower in energy than those found previously.Determining the structure of a molecule, cluster or crystal is one of the most fundamental and important tasks in solid state physics and chemistry. Practically all physical properties of a system depend on its structure. The structural configurations of a system are determined by the Born-Oppenheimer PES, which gives the energy of a system as a function of its atomic coordinates. Minima of the PES give stable configurations. The global minimum gives the ground state configuration. At low enough temperature the system will be found in this global minimum structure assuming that this structure is kinetically accessible. Since the zero point energy of different structures varies negligibly, the determination of the ground state structure is equivalent to the mathematical problem of finding the global minimum of the PES.It is well established that the PES of a condensed matter system can be calculated with good accuracy within DFT. Nevertheless, DFT methods have not been used up to now as a standard tool in algorithms that attempt to determine the ground state of complex systems because most algorithms for the determination of the global minimum require an enormous number of evaluations of the PES. Since each evaluation requires a full electronic structure calculation, these algorithms are computationally too demanding within the full DFT framework. A systematic search for the global minimum is however possible with cheaper methods such as tight binding and force field methods.In summary, with present methods one has either the choice of using methods with a limited power of predictability or of doing a constrained search for the global minimum. In a constrained search one fixes some atomic positions or imposes some structural motifs, but experience shows that the global minimum is often missed in this way. To overcome this dilemma several researchers have adopted an approach where one first effectuates a systematic search with a method that allows for a fast but inaccurate calculation of the PES to obtain some candidate structures. Which of the candidate structures is lowest in energy is determined in a second step by DFT calculations. As we shall show later this approach is generally not applicable.Other researches have combined systematic search algorithms with DFT methods, but their algorithms required too many DFT calculations to be com...

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“…Several recent publications are focusing on the study of small eiemental silicon clusters using ab initio methods [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Ab initio investigation of the stability of Si3C3 clusters and their structural and bonding features

Mühlhäuser

Froudakis

Zdetsis

et al. 1994

Z Phys D - Atoms, Molecules and Clusters

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Abstract. Various structural possibilities for Si 3 C 3 clusters are investigated by ab initio calculations employing basis sets of double-and triple-zeta quality augmented by d polarization functions. Correlation effects are included by a second-order Moeller Piesset perturbation treatment. For the two lowest-lying structures higher-order correlation corrections and multi-reference effects are also included. Bonding features are investigated by two different types of population analyses to obtain insight into the nature of chemical bonding. A total of 17 stationary points were investigated, 14 of which correspond to local minima and three being transition states. The energetically lowest-lying structures are: A "pyramidlike" structure with various multicenter bonds, followed by a es symmetric isomer closely related to the ground state Si 6 structure. Planar structures, favoured in small carbon clusters, lie higher in energy and are transition states. The lowest-lying triplet system is found to be the linear nonsymmetric Si -C-C-C-Si -Si structure, which is calculated to lie about 38 kcalfmole above the singlet ground state. A building-up principle based on bonding criteria is suggested for the occurence of the various structural possibilities.

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Electronic structures of the negative ions Si−2 –Si−10: Electron affinities of small silicon clusters

Cited by 185 publications

References 78 publications

Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n

Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n

Global Minimum Determination of the Born-Oppenheimer Surface within Density Functional Theory

Ab initio investigation of the stability of Si3C3 clusters and their structural and bonding features

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Electronic structures of the negative ions Si−2 –Si−10: Electron affinities of small silicon clusters

Cited by 185 publications

References 78 publications

Electronic and geometric structures of Sin– and Sin+ (n = 2–10) clusters and in comparison with Sin

Electronic and geometric structures of Sin– and Sin+ (n = 2–10) clusters and in comparison with Sin

Global Minimum Determination of the Born-Oppenheimer Surface within Density Functional Theory

Ab initio investigation of the stability of Si3C3 clusters and their structural and bonding features

Contact Info

Product

Resources

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Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n

Electronic and geometric structures of Si_n^– and Si_n⁺ (n = 2–10) clusters and in comparison with Si_n