All-boron analogues of aromatic hydrocarbons: B17− and B18−

Sergeeva, Alina P.; Аверкиев, Борис Б.; Zhai, Hua‐Jin; Boldyrev, Alexander I.; Wang, Lai-Sheng

doi:10.1063/1.3599452

Cited by 300 publications

(229 citation statements)

References 82 publications

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“…In contrast, the Coalescence Kick (CK) method 30 generates initial structures in a dynamical way: the randomly positioned atoms are pushed toward the center of mass step by step until all connected. The CK method is equivalent to setting an upper bound of l 1 and obtaining a more natural distribution of l 1 at the shorter bond length side.…”

Section: Methodsmentioning

confidence: 99%

Ensemble-Average Representation of Pt Clusters in Conditions of Catalysis Accessed through GPU Accelerated Deep Neural Network Fitting Global Optimization

Zhai

Alexandrova

2016

J. Chem. Theory Comput.

133

207

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We first report a global optimization approach based on GPU accelerated Deep Neural Network (DNN) fitting, for modeling metal clusters at realistic temperatures. The seven-layer multidimensional and locally connected DNN is combined with limited-step Density Functional Theory (DFT) geometry optimization to reduce the time cost of full DFT local optimization, which is considered to be the most time-consuming step in global optimization. An algorithm based on bond length distribution analysis is used to efficiently sample the configuration space and generate random initial structures. A structure similarity measurement method based on depth-first search is used to identify duplicates. The performance of the new approach is examined by the application to the global minimum searching for Pt 9 and Pt 13 . The ensemble-average representations of the two clusters are constructed based on all geometrically different isomers, on which the structure transition is predicted at low and high temperatures, for Pt 9 and Pt 13 clusters, respectively. Finally, the ensemble-averaged vertical ionization potential changes when temperature increases, and the property in conditions of catalysis can be different from that evaluated at the global minimum structure.

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Section: Methodsmentioning

confidence: 99%

Ensemble-Average Representation of Pt Clusters in Conditions of Catalysis Accessed through GPU Accelerated Deep Neural Network Fitting Global Optimization

Zhai

Alexandrova

2016

J. Chem. Theory Comput.

133

207

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“…Through a joint study of photoelectron spectroscopy and ab initio computation, Boldyrev and Wang confirmed that anionic boron clusters with up to nineteen atoms are planar or quasi-planar [18,19]. And a particularly attractive…”

Section: Planar Boron Clustersmentioning

confidence: 95%

Geometries and Electronic Structures of Boron Clusters: Planar Structures and All-boron Fullerenes

Liu¹

2016

J Apl Theol

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[5]. Thus, they attract the interests of interdisciplinary researchers. A primary task in the research of boron clusters is to find the most stable structures of clusters containing given numbers and types of atoms. In this mini-review, we summarize the geometries and electronic structures of two commonly studied boron clusters, planar boron clusters and all-boron fullerenes. Planar Boron ClustersIn the solid state, boron compounds often adopt threedimensional (3D) structures [6][7][8][9][10]. One heavily studied type is boranes of general form B n H n . Most of the boranes are shown to be cage-like, referred as deltahedra [11]. The representative example is B 12 H 12 2− , which was first theoretically investigated by Longuet-Higgins and Roberts using molecular orbital theory [12]. They concluded that the B 12 H 12 structure could be stable only as a di-anion, B 12 H 12 2− , having 13 skeletal bonding orbitals and 12 outward pointing external orbitals. This hypothesis was confirmed later by experimental data, and the structure of B 12 H 12 2− anion was shown to be icosahedral [13]. Unlike 3D cage structures, which are the dominant configurations of boron compounds in the solid state, the pure small boron clusters (n ≤ 40) are found to be two-dimensional (2D) planar or quasi-planar in the gas phase, and the chemical bonding analysis suggests that this planarity is a consequence of π bonding in the cluster forms [9,10]. The simplest pure boron cluster is the diatomic B 2 , which serves as the first example of unusual chemical bonding in the boron species. On the basis of Hartree-Fock and UMP4 (unrestricted fourth order Møller-Plesset perturbation theory) calculations [14], the next pure boron cluster, B 3 , is shown to exist in cationic or anionic forms with a triangular structure of D 3h symmetry.In 2004, Zubarev et al concluded that pure boron clusters containing up to 15 atoms retain planar or quasi-planar conformation [15]. However, there still remains a strong interest to determine the critical size at which structural transition from 2D to 3D occurs. This, however, is a challenging task due to the complexity of these systems and the existence of a large number of isomers. Such 2D-to-3D structural transition is also strongly affected by the charges of boron clusters. For cationic boron clusters (B n + ), the largest planar or quasi-planar structure was established for n=15, and the transition from planar to cylindrical structure takes place for B 16 + [16]. Combining experiment (photoelectron spectroscopy) with computational studies (global minimum search), Kiran et al [17]found that the neutral B 20 cluster undergoes a 2D-to-3D structural transition, resulting in formation of a stable double-ring tubular structure with a diameter of 5.2 Å (Figure 1). The tubular structure was considered as the embryo of the thinnest single-walled boron nanotubes.However, the upper limit for the B n − anionic clusters still remains an open question. Through a joint study of photoelectron spectroscopy and ab initio computatio...

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“…The geometric search was performed using Gaussian, with starting configurations generated at random using the coalescence kick method (CK-Search) [21,22]. This method has been employed successfully by many groups to study small clusters.…”

Section: Methodsmentioning

confidence: 99%

Interior Melting of the C3B16 and C2B14− Clusters Between 1000 K and 2000 K

Yang

Ganz

2017

Condensed Matter

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For bulk three-dimensional materials, it is common for the surface to melt at a slightly lower temperature than the bulk. This is known as surface melting, and is typically due to the fact that there are fewer bonds to surface atoms. However, for small clusters, this picture can change. In recent years, there have been investigations of the B 19 and B 19 − clusters, which show striking diffusive behavior as they are heated to 1000 K. We wondered what the effect of substituting a few carbon atoms would be on the properties of these small clusters. To this end, we carried out extensive structural searches and molecular dynamics simulations to study the properties of C 3 B 16 and C 2 B 14 − at elevated temperatures. The ground state structures and lowest energy isomers for these clusters were determined and calculated. The lowest energy structures are two-dimensional with vacancies inside. The C atoms are located in the outer ring in the ground state. At 1400 K, the outer rim containing the carbon atoms has fixed bonding, while the interior atoms are able to diffuse freely. Therefore, both of these clusters display interior melting at 1400 K. This interior melting is explained by the larger bond strength of the rim atoms. Molecular dynamics simulations at 3000 K showed complete melting and we observed a wide variety of configurations in both clusters.

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All-boron analogues of aromatic hydrocarbons: B17− and B18−

Cited by 300 publications

References 82 publications

Ensemble-Average Representation of Pt Clusters in Conditions of Catalysis Accessed through GPU Accelerated Deep Neural Network Fitting Global Optimization

Ensemble-Average Representation of Pt Clusters in Conditions of Catalysis Accessed through GPU Accelerated Deep Neural Network Fitting Global Optimization

Geometries and Electronic Structures of Boron Clusters: Planar Structures and All-boron Fullerenes

Interior Melting of the C3B16 and C2B14− Clusters Between 1000 K and 2000 K

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