Electronic and atomic stuctures of Sb4 and Sb8 clusters.
TL;DR: The electronic and atomic structure of Sb 4 and Sb 8 clusters is studied using the ab initio molecular dynamics method in the local density approximation, indicating the importance of the bent rhombus structure for larger clusters.
Abstract: The electronic and atomic structure of Sb 4 and Sb 8 clusters is studied using the ab initio molecular dynamics method in the local density approximation. While for Sb 8 a regular tetrahedron is about 2.0 eV lower in energy than a bent rhombus, for Sb 8 two weakly interacting tetrahedra lie only 0.117 eV lower in energy than a bent rhombus interacting with a stretched tetrahedron, indicating the importance of the bent rhombus structure for larger clusters. The binding energy of Sb 8 relative to two noninteracting tetrahedra is about 0.5 eV. These results are in excellent agreement with the experimental data
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TL;DR: In this article, the electronic structure and chemical bonding of the pentapnictogen cluster anions, Pn5- (Pn = P, As, Sb, and Bi), were investigated using both photoelectron spectroscopy and ab initio calculations.
Abstract: The electronic structure and chemical bonding of the pentapnictogen cluster anions, Pn5- (Pn = P, As, Sb, and Bi), were investigated using both photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra were obtained for the anions at several photon energies and were analyzed according to the theoretical calculations. The ground state of all the Pn5- species was found to be the aromatic cyclic D5h structure with a C2v low-lying isomer. We found that the C2v isomer gains stability from P5- to Sb5-, consistent with the experimental observation of the coexistence of both isomers in the spectra of Sb5-. The valence molecular orbitals (MOs) of the D5h Pn5- were analyzed and compared to those of the aromatic C5H5- hydrocarbon. The same set of π-MOs is shown to be occupied in the D5h Pn5- and C5H5- species, except that the MO ordering is slightly different. Whereas the three π-MOs in C5H5- all lie above the σ-MOs, the third π orbital (1a2‘ ‘ in Pn5-) lies below the σ-MOs. The stab...
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TL;DR: In this paper, the pseudopotential plane wave method was used to predict relative stability and composition-dependent properties of binary clusters at the same quality level as all electron calculations, and the results showed that with sufficient accuracy in numerical computation, the pseudoprocessor was capable of predicting relative stability of the binary clusters.
Abstract: ${\mathrm{Ga}}_{m}{\mathrm{As}}_{n}$ clusters with $m+n=2,4,\dots{},16$ are studied using first-principles methods based on density functional theory. We demonstrate that with sufficient accuracy in numerical computation, the pseudopotential--plane-wave method is capable of predicting relative stability and composition-dependent properties of the binary clusters at the same quality level as all electron calculations. The calculated binding energy of the ${\mathrm{Ga}}_{m}{\mathrm{As}}_{n}$ clusters decreases with increasing Ga to As ratio in the clusters, and as expected, binary clusters are energetically favored compared to pure metal clusters of Ga and As formed with the same numbers of atoms. The highest occupied molecular orbital-lowest unoccupied molecular orbital gap decreases as a function of Ga concentration in the clusters, while the electron affinity and ionization energy show weak dependence on composition. The electron affinity increases slowly with Ga to As ratio, but the ionization energy shows a decreasing trend. However, there are large fluctuations in the predicted composition-dependent physical properties.
20 citations
TL;DR: In this article, the atomic and electronic structure of SbN (N=2-8 and 12) clusters within the local density approximation and pseudopotential representation of the electron-ion interaction was studied.
Abstract: We present an ab initio molecular dynamics study of the atomic and electronic structure of SbN (N=2–8 and 12) clusters within the local density approximation and pseudopotential representation of the electron–ion interaction. Simulated annealing calculations have been done for 6‐, 7‐, 8‐, and 12‐atom clusters. While for Sb4 a bent rhombus is about 2 eV higher in energy than a regular tetrahedron, we find that it plays an important role in the structure of larger clusters. For Sb8 we obtain two weakly interacting tetrahedra to be of lowest energy. However, this is nearly degenerate with a bent rhombus interacting with a distorted tetrahedron. Further, our calculations suggest a bent rhombus based structure for Sb12 cluster indicating the observation of Sb4n clusters in Sb vapor condensation cell to be due to abundance of Sb4 clusters. A large gap is found to exist between the highest and the next occupied Kohn–Sham eigenvalues of the lowest energy isomers of 3‐, 5‐, and 7‐atom clusters. This is in agreemen...
19 citations
TL;DR: In this article, the growth of thin antimony films on the Au(1.1) surface at room temperature was studied by scanning tunneling microscopy (STM) in ultrahigh vacuum.
18 citations
TL;DR: In this paper, it is shown that the electronic structure plays an important role in the atomic structure and related properties of other magic clusters, such as rare gases, metals, covalently bonded systems and water.
17 citations