On the energetic and magnetic stability of potassium atomic clusters doped by yttrium.

The abstract should be a single paragraph which summarises the content of the article. This study utilizes density functional theory (DFT) calculations to explore the energetic and magnetic stability of neutral and charged potassium (K) clusters doped with yttrium (Y). We aim to elucidate the influence of Y doping on the energetics and structures of these clusters, comparing them to undoped K clusters. Ground states of 64 polyhedral structures, all of them encapsulating at least one Y atom, were obtained. Y doping generally increased the spin magnetic moment, with charged clusters exhibiting the highest values. Notably, the K12Y+ cluster, possessing an icosahedral geometry and a magnetic moment of 6µB, is classified as a magnetic superatom. Additionally, we identified 14 superatoms with high magnetic robustness. The density of states (DOS) and spin density calculations additionally highlighted the substantial role played by yttrium in the electronic density of the electrons responsible for inducing magnetism in these clusters.

On the energetic and magnetic stability of neutral and charged lithium clusters doped with one and two yttrium atoms.

DFT calculations were performed to study the effect on energetic and magnetic stability when clusters with up to 24 lithium atoms were doped with one and two atoms of yttrium. In this, the effect of the charge was considered. As a result, some stable structures were identified as possible magnetic superatoms, among them, the YLi12+ cluster with an icosahedron geometry with a spin magnetic moment of 4 bohr magnetons. The participation of yttrium in the electron density of the unpaired electrons providing magnetism in clusters was corroborated at the level of a density of states (DOS) calculation and a spin density calculation. In particular, in the Y2Li12+ superatom, it was found that the encapsulated yttrium atom participates with 35.02% and the second yttrium atom with 15.04%. These percentages, with a contribution from p orbitals, but to a greater extent by d orbitals. The complementation to these percentages is due to the participation of the s and p orbitals of the lithium atoms. In general, doping with a second yttrium atom allowed to obtain a greater amount of high magnetic moments, and considering charged clusters allowed to obtain also high magnetic moments.

Calculation of the EPR g-tensor from auxiliary density functional theory.

The working equations for the calculation of the electron paramagnetic resonance (EPR) g-tensor within the framework of the auxiliary density functional theory (ADFT) are presented. The scheme known as gauge including atomic orbitals (GIAOs) is employed to treat the gauge origin problem. This ADFT-GIAO formulation possesses an inherent high computational performance, allowing for the calculation of the EPR g-tensor of molecules containing some hundreds of atoms in reasonable computational time employing moderate computational resources. The effect of the use of a gauge independent auxiliary density on the quality of the g-tensor calculation for the evaluation of the exchange-correlation contribution is analyzed in this work. The best agreement with the experiment is obtained with the BLYP functional (Becke 1988 exchange and Lee-Yang-Parr correlation) in combination with a double-ζ basis set, in particular aug-cc-pVDZ. Furthermore, models of endohedral fullerenes N@Cn, with n = {60, 70, 100, 180, 240}, were used for benchmarking its computational performance.