Does spin–orbit coupling effect favor planar structures for small platinum clusters?

Abstract

We have performed full-relativistic density functional theory calculations to study the geometry and binding energy of different isomers of free platinum clusters Pt n (n = 4 − 6) within the spin multiplicities from singlet to nonet. The spin-orbit coupling effect has been discussed for the minimum-energy structures, relative stabilities, vibrational frequencies, magnetic moments, and the highest occupied and lowest unoccupied molecular-orbital gaps. It is found in contrast to some of the previous calculations that 3-dimentional configurations are still lowest energy structures of these clusters, although spin-orbit effect makes some planar or quasi-planar geometries more stable than some other 3-dimentional isomers.

Spin-orbit coupling effects in gold clusters: The case of Au13

“…It is dependent of the cluster shape and is stronger for planar isomers. The second observation is that the effects of SO coupling on the average atomic distances are monotonic, contrary to previous results reported for Pt clusters [17,18] where relativistic effects are also very strong. We note that bond contractions are increased when the semi core states are considered as valence electrons.…”

Communication: The structures of small cationic gas-phase platinum clusters

“…[1][2][3][4] In contrast, despite platinum being much more widely used in catalysis than gold, there are no structural or spectroscopic characterizations of platinum clusters larger than the trimer. There have been significant theoretical efforts to investigate the structures of isolated platinum clusters, [5][6][7][8][9][10][11] but so far these are inconclusive, predicting different lowenergy structures. Here, we present a combined experimental and computational study of small platinum clusters to determine the structures of Pt + n (n = 3-5) and investigate what level of theory is necessary to treat these systems reliably.…”

First principles studies of Fe m Ir n (2 ≤ m + n ≤ 4) nano clusters

“…The inclusion of spin-orbit coupling (SOC) is needed for the calculations involving magnetic anisotropic energy (MAE), as MAE originates from the coupling between the spin and orbital degrees of freedom. SOC is also known to affect the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps in 5d clusters as has been shown by Sebetci (2008). However, the theme of the present study is to calculate the relative stability and magnetic moment of the clusters and calculation of orbital moments and MAE may be the subject of a future study.…”