Structure and properties of small silicon and aluminum clusters

Jug, Karl; Schluff, Hans‐Peter; Kupka, Hans; Iffert, Rüdiger

doi:10.1002/jcc.540090802

Cited by 36 publications

(17 citation statements)

References 30 publications

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“…DFT calculation shows that the most stable form of Al 3 is an equilateral triangle, in agreement with the work of Pettersson et al 1 For Al 4 the planar rhombus ͑D 2h ͒ conformation is found to be more stable than the pyramidal form ͑C 3v ͒, in agreement with Koutecky et al 43 and Pettersson et al 1 In the case of Al 5 , Jug et al 44 found the pyramidal form to be the most stable, whereas Petterson et al 1 and Yang et al 9 found the planar ͑C 2v ͒ form to be more stable than the pyramidal form. The DFT calculations for Al 5 are consistent with the works of Yang et al 9 In addition, Pettersson et al 1 found that in the case of Al 6 the octahedron is the most stable form, whereas Upton 2 found a distorted octahedron to be the most stable.…”

Section: A Heats Of Formation and Geometry Of Clusterssupporting

confidence: 86%

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Ojwang

Santen

Kramer

et al. 2008

The Journal of Chemical Physics

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A parametrized reactive force field model for aluminum ReaxFF Al has been developed based on density functional theory ͑DFT͒ data. A comparison has been made between DFT and ReaxFF Al outputs to ascertain whether ReaxFF Al is properly parametrized and to check if the output of the latter has correlation with DFT results. Further checks include comparing the equations of state of condensed phases of Al as calculated from DFT and ReaxFF Al . There is a good match between the two results, again showing that ReaxFF Al is correctly parametrized as per the DFT input. Simulated annealing has been performed on aluminum clusters Al n using ReaxFF Al to find the stable isomers of the clusters. A plot of stability function versus cluster size shows the existence of highly stable clusters ͑magic clusters͒. Quantum mechanically these magic clusters arise due to the complete filling of the orbital shells. However, since force fields do not care about electrons but work on the assumption of validity of Born-Oppenheimer approximation, the magic clusters are therefore correlated with high structural symmetry. There is a rapid decline in surface energy contribution due to the triangulated nature of the surface atoms leading to higher coordination number. The bulk binding energy is computed to be 76.8 kcal/mol. This gives confidence in the suitability of ReaxFF for studying and understanding the underlying dynamics in aluminum clusters. In the quantification of the growth of cluster it is seen that as the size of the clusters increase there is preference for the coexistence of fcc/hcp orders at the expense of simple icosahedral ordering, although there is some contribution from distorted icosahedral ordering. It is found that even for aluminum clusters with 512 atoms distorted icosahedral ordering exists. For clusters with N Ն 256 atoms fcc ordering dominates, which implies that at this point we are already on the threshold of bulklike bonding.

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Section: A Heats Of Formation and Geometry Of Clusterssupporting

confidence: 86%

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Ojwang

Santen

Kramer

et al. 2008

The Journal of Chemical Physics

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“…It goes back to the middle of the 1980s that a number of theoretical studies of Al clusters have been carried out by different groups [20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39]. These studies range from the simple jellium model [20] where the cluster geometry is ignored, to a number of models where the geometry explicitly enters into the picture including semiempirical molecular orbital calculations [21], quantum molecular dynamics [26,27,28,29,31], quantum-mechanical calculations based on quantumchemical [22,23,24] and density-functional [25,26,27,28,29,30,31,32,33] theories (DFT) within local density or local spin-density approximations, molecular dynamics and Monte Carlo simulations based on empirical model potentials [34,35,36,37,38,39]...…”

Section: A Aluminium Clustersmentioning

confidence: 99%

Global minima of Al_N, Au_Nand Pt_N,N⩽ 80, clusters described by the Voter–Chen version of embedded-atom potentials

Sebetci

Güvenç

2005

Modelling Simul. Mater. Sci. Eng.

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Using the basin-hopping Monte Carlo minimization approach we report the global minima for aluminium, gold and platinum metal clusters modelled by the Voter-Chen version of the embeddedatom model potential containing up to 80 atoms. The virtue of the Voter-Chen potentials is that they are derived by fitting to experimental data of both diatomic molecules and bulk metals simultaneously. Therefore, it may be more appropriate for a wide range of the size of the clusters. This is important since almost all properties of the small clusters are size dependent. The results show that the global minima of the Al, Au and Pt clusters have structures based on either octahedral, decahedral, icosahedral or a mixture of decahedral and icosahedral packing. The 54-atom icosahedron without a central atom is found to be more stable than the 55-atom complete icosahedron for all of the elements considered in this work. The most of the Al global minima are identified as some fcc structures and many of the Au global minima are found to be some low symmetric structures, which are both in agreement with the previous experimental studies.

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“…Our results are in agreement with previous Hartree-Fock [23] and DFT [30] studies which indicate the rhombus structure as the absolute minimum in the potential energy surface. A Generalized Valence Bond investigation [9] gives a three-dimensional deformed rhombus as the ground state, whereas semiempirical computations prefer the trigonaI pyramid coming from a Jahn-Teller distortion of a tetrahedral structure [24].…”

Section: A14 A1 + A17mentioning

confidence: 99%

Gaussian density-functional study for small neutral (Al n ), positive (Al+ n ) and negative (Al− n ) aluminium clusters (n=2–5)

Calaminici

Russo

Toscano

1995

Z Phys D - Atoms, Molecules and Clusters

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Abstract. The structures and properties of AI,, A1 +, AI~-(n = 1, 5) clusters have been investigated by using the Linear Combination of Gaussian Type Orbitals (LCGTO) method, considering Local (LSD) and Non Local (NLSD) Spin Density Approximations and employing a Model Core Potential (MCP) that allows the explicit treatment of 3S 2 3p 1 valence electrons. For each system different geometrical structures and electronic states have been considered. For A13, AI~-, At2 the most stable geometry proved to be the equilateral triangle (D3h). AI4 and At2 prefer the rhombus (D2h) structure, while the corresponding anion prefers the square (D4h) one. The trapezoidal form (C2~) is the most stable isomer for A15, AI~ ~ and A1;-clusters. The analysis of vibrational frequencies shows that these structures are minima in the potential energy surface. The binding energies (De), the adiabatic ionization potentials (IP) and electron affinities (EA), the chemical potentials or absolute hardnesses (r/) and electronegativities (X) have been computed. Results are in good agreement with the available experimental data and the previous high level theoretical computations.

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Structure and properties of small silicon and aluminum clusters

Cited by 36 publications

References 30 publications

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Global minima of Al_N, Au_Nand Pt_N,N⩽ 80, clusters described by the Voter–Chen version of embedded-atom potentials

Gaussian density-functional study for small neutral (Al n ), positive (Al+ n ) and negative (Al− n ) aluminium clusters (n=2–5)

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Structure and properties of small silicon and aluminum clusters

Cited by 36 publications

References 30 publications

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field

Global minima of AlN, AuNand PtN,N⩽ 80, clusters described by the Voter–Chen version of embedded-atom potentials

Gaussian density-functional study for small neutral (Al n ), positive (Al+ n ) and negative (Al− n ) aluminium clusters (n=2–5)

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Global minima of Al_N, Au_Nand Pt_N,N⩽ 80, clusters described by the Voter–Chen version of embedded-atom potentials