Structural evolution and stabilities of (PbTe)n(n = 1–20) clusters

The geometric and electronic structures of lead telluride clusters are investigated numerically. The result provided both vertical and adiabatic electron affinities (VEAs and AEAs) for this clusters, revealing a pattern of alternating values in which even n clusters exhibited lower values than odd n clusters up until n = 8 and beyond n = 14 . Computations found lead telluride clusters with even n to be thermodynamically more stable than their immediate odd n neighbors, with a consistent pattern also being found in their HOMO–LUMO gaps. Analysis of cluster dissociation energies found at Pb 4 Te 4 cube to be the preferred product of the queried fragmentation processes, consistent with our finding that Pb 4 Te 4 cluster exhibits enhanced stability; it is a magic number species. Beyond n = 10 , this study showed that the ( PbTe ) n clusters in the size range n = 11 – 20 , prefer two dimensional stacking of face-sharing lead telluride cubical units, where lead and tellurium atoms possess a maximum of fivefold coordination. The preference for sixfold coordination, which is observed in the bulk, was not observed at these cluster sizes.