In this article, we report the relativistic electronic structure, including spin-orbit interaction, employing all-electron density functional theory calculations on the multimetallic sandwich compound [(CNT)Pd4(COT)]1+ (1), which can be considered as a [Pd4]2+ fragment flanked by two ring-ligands, namely, cyclononatetraenyl (CNT1−) and cyclooctatetraene (COT), as well as the dimer of 1, hereafter 2. The calculations suggest that the Pd4-ligand interaction is mainly electrostatic, being the main responsible term for the stabilization of the almost fully occupied 4d shell [Pd4]2+ fragment. The ring currents and electronic delocalization estimated via the nuclear independent chemical shifts indices and electron localization function, allow us to describe a significant σ-aromaticity at the center of the Pd4 square in 1, which in conjunction with the aromaticity arising from the ligands induce considerable aromatic character inside of the multimetallic metallocene.

In the present work, the lowest energy structures and electronic properties of Ag_n clusters up to n = 16 are investigated using a successive growth algorithm coupled with density functional theory calculations (DFT).