Structures and Stabilities of Pb_n (n ≤ 20) Clusters

Abstract

We have performed global structural optimizations for neutral lead clusters Pb(n) (n = 2-20) by using a genetic algorithm (GA) coupled with a tight-binding (TB) potential. The low-energy structures identified from a GA/TB search were further optimized at the DFT-PBE level. The calculated results show that the Pb(n) (14 < n </= 20) clusters favor compact spherical structures with hexagon and pentagon rings. These structures are different from those of Si(n), Ge(n), and Sn(n) clusters which favor prolates in the same size range. The binding energies, second differences in energy, and fragmentation behaviors of the Pb(n) clusters were also discussed. Pb(n) (n = 4, 7, 10, 13, 15, and 17) clusters are found to be special stable clusters, which is in good agreement with the experimental results.

Structural evolution and metallicity of lead clusters

“…The GM 19a is a C 2 symmetric structure similar to the GM reported by Ho and coworkers. 13 It has a moderate dipole moment of 0.72 D and its simulated beam profile well describes the experimental data. Isomer 19b is a peculiar structure consisting of Pb 9 and Pb 10 subunits only 0.02 eV above the GM; this geometry has a dipole moment of 1.82 D and the corresponding beam profile is significantly broadened.…”

“…Several theoretical studies are dedicated to neutral Pb cluster. [12][13][14] Wang et al calculated gaps between highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO) as well as densities of states up to Pb 22 using density functional theory (DFT). 15 They observed gaps around 1 eV for their largest cluster investigated and a considerable dependence on the geometric structure.…”

Exploring the potential energy surface of small lead clusters using the gradient embedded genetic algorithm and an adequate treatment of relativistic effects

“…Our interest in these systems is due to the abundant experimental and theoretical studies concerning their structural elucidation when compared with our results. [15][16][17][18][19][20][21][22][23] From an experimental view, small lead clusters have been obtained via laser vaporization and determined by ion mobility, 16,24-28 gas phase ion electron diffraction, [27][28][29] and photoionization mass spectrometry. 21,[30][31][32] In these studies, "magic" numbers were observed in size distributions under a variety of ionization conditions.…”

Photoelectron velocity-map imaging signature of structural evolution of silver-doped lead Zintl anions

“…[1][2][3][4] A large number of "ligand-free" Group 14 Zintl clusters have been prepared via the synthesis in the liquid phase or the laser vaporization in the gas phase, of which geometric and electronic structures have been explored experimentally and theoretically. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] In particular, the identifications of highly symmetric cage structures of the fascinating Pb 10 2− , Sn 12 2− , and Pb 12 2− clusters [10][11][12][13] intrigue and invite investigation of the metal-doped Zintl clusters [10][11][12] in the knowledge of whether a doped atom is endohedral or exohedral. Most of this work has involved the heavy Group 14 element species with the magic cluster size number of 10 and 12.…”