Structures of Pb_n(n= 21–30) clusters from first-principles calculations

Abstract

Neutral lead clusters Pb(n) (n = 21-30) were studied using a genetic algorithm (GA)/tight-binding (TB) search combined with density functional theory (DFT)-Perdew-Burke-Ernzerhof (PBE) calculations. The calculated results show that the Pb(n) (22 ≤ n ≤ 30) clusters favor endohedral cage structures with two (Pb(22 - 26)) or three (Pb(27 - 30)) endohedral atoms. The binding energies, stabilities, and highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of the Pb(n) clusters were also discussed. The results from our calculations also indicate that Pb(24) and Pb(28) are especially stable clusters compared with their neighbors.

Structural evolution and metallicity of lead clusters

“…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.…”

Metal-loaded zeolites in ammonia decomposition catalysis

“…designated as magic number clusters with particularly high stability. 58 In particular, they calculate the ground state structures of Ru 5 and Ru 6 to be an optimised square pyramid and hexagonal prism respectively. Using these as a basis, two such DFT-optimised models fitting experimental Ru–Ru and Ru–O/N CNs – a Ru 5 N 5 pyramidal cluster and a Ru 6 N 6 prismatic cluster (Fig.…”

Multifaceted Thermodynamics of Pbn (n = 16–24) Clusters: A Case Study

“…We begin our discussion by presenting the putative global minima for Pb clusters in the size range 16–24, shown in Figure . We began our search for the GS from the previously published data. ,− Nearly 3–5 ns of BOMD was performed for each size, the details of which are noted in Table . About a thousand initial positions were optimized from the MD for each size, before concluding the search for their GS.…”

“…Previous investigations about Pb clusters in this size range concern their geometries, bonding, electric dipole moments, and electronic structures. − However, with the exception of work done by Pushpa et al, there exist no first principle studies that discuss the thermodynamics of small clusters of Pb . In their work, Pushpa et al relate the stiffness of bonds in small (<20 atoms) Pb clusters to their melting.…”