A DFT study was carried out on the ground state structures of ternary CulAgmAun (l + m + n = 6) clusters, with the aim of investigating changes of thermal and kinetic stabilities as an effect of composition, as well as the composition dependence of the electrostatic potential, of stable planar structures. DFT optimizations were performed using the PBE functional and the SDD basis set. All the optimized structures adopt planar geometries with bent triangular structures. Calculated binding energy values are in the range 1.5–1.9 eV/atom, which shows their thermal stability. The predicted HOMO‐LUMO energy gap values are in the semiconductor region, providing a qualitative indication of a moderate kinetic stability. NBO analyses indicate the existence of two mechanisms promoting planar structural stability, one due to bonding‐antibonding orbital interaction, and the other one due to the well‐known spd hybridization. Wiberg indices were obtained showing interatomic bonding. Electrostatic potential calculations show the existence of nucleophilic attack regions preferentially around silver and copper atoms located at the vertices while electrophilic attack regions are found in the vicinity of gold atoms over the cluster plane. Apparently, charge transfer occurs toward gold from silver and copper atoms when the concentration is favorable in the proximity of gold atoms. In particular, if the small ternary clusters discussed here contain only one gold atom, then a high electron density is observed at the site of this gold atom. © 2016 Wiley Periodicals, Inc.

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In this work we have performed a systematic study of new organometallic complexes containing penta- and heteropentadienyl (CH2CHCHCHX, X = CH2, O, NH, S) ligands coordinated to beryllium. Calculated complexes were studied using the density functional theory (PBE) in combination with the 6-311++G(3d,2p) basis set. The coordination number on the beryllium atom varies according to the type of ligand. Pentadienyl ligand shows hapticities η(1) and η(5), while heteropentadienyl ligands display η(1) and η(2) hapticities. A Wiberg bond indices study was performed in order to get information about their bond orders.

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A series of penta- and heteropentadienyl [CHCHCHCHXBe], (X = CH, O, NH, S) complexes has been theoretically studied. All calculated complexes show beryllium atoms with two, three, and five coordination numbers. The density functional theory (DFT) was used to determine the electron and structural behavior of those beryllium complexes. The nature of the ligands plays an important role in the form of binding to the beryllium atom. Beryllium structures 1-4 are able to coordinate only one hydrogen molecule. A molecular orbital analysis for all complexes was performed in order to know more about the nature of their bonding scheme.