Small copper-doped silicon clusters CuSin (n = 4–10) and their anions: structures, thermochemistry, and electron affinities

Pairwise Model Potential and DFT Study of Li+Nen Clusters (n = 1-20): The Structural, Electronic, and Thermodynamic Properties

The structural properties, relative stabilities, electronic, and thermodynamic properties, of Li+Nen (n = 1-20) clusters have been studied based on a pairwise model and density functional theory (DFT) methods. In the pairwise method, the potential energy surface considered interactions between Li+Ne, Ne - Ne, and many-body term. For the DFT calculations, the B3LYP functional combined with the 6-311 + + G (2d,2p) basis sets has been employed. In both methods, the Li+Ne6 cluster demonstrated high stability with an octahedral structure, where the Li+ cation was surrounded by Ne atoms. Thus, the octahedral Li+Ne6 structure was considered to be the core for larger cluster sizes. Relative stabilities were assessed based on binding energies, second-order differences of energies, transition dipole moment, and HOMO-LUMO energy gaps. Furthermore, thermodynamic properties were calculated, revealing that the formation process of Li+Nen clusters is endothermic and nonspontaneous.

Structural and electronic properties of nanosize semiconductor HfSin0/-/2- (n = 6-16) material: a double-hybrid density functional theory investigation

Equilibrium geometries, thermodynamic stabilities, chemical reactivities, and electronic properties of neutral, mono-, and di-anionic Hf-doped silicon nanoclusters HfSi_n^0/-2- (n = 6-16) are calculated by employing an ABCluster global search technique combined with mPW2PLYP scheme. Based on the concordance between simulated and experimental PES, the true global minima are confirmed for n = 6, 9, and 12-16. Optimized geometries for neutral HfSi_n nanoclusters can be divided into three stages: first, Hf atom prefers locating on the surface site of the cluster for n = 6-9, which can be obtained by adding one, two, three, and four Si atoms to HfSi₅ tetragonal bipyramid, respectively (denoted as additive type); then, Hf atom is surrounded by Si atoms with half-cage configuration for n = 10-13; finally, Hf atom is encapsulated into Si cage pattern for n = 14-16. For mono-anions, it is from additive type (n = 6-11) to the cagelike configuration with Hf atom resided in silicon clusters (n = 12-16). For di-anions, it is additive type (n = 6-9) to the Hf-linked configuration (n = 10-11), and in the end to the Hf-encapsulated cagelike motif (n = 12-16). The thorough analysis of stability and chemical bonding revealed that the neutral HfSi₁₆ and di-anionic HfSi₁₅^2- are magic nanoclusters with good thermodynamic and chemical stability, which may make them as the most suitable building block for new functional materials. We suggest that the experimental PES of HfSi_n^- with n = 7, 8, 10, and 11 should be further examined due to the lack of comparably low electron binding energy peaks.

Structural determination of niobium-doped silicon clusters by far-infrared spectroscopy and theory

The structures of niobium doped silicon cluster cations are determined by a combination of infrared multiple photon dissociation spectroscopy and density functional theory calculations.