Structural Evolution, Electronic Structures, and Vibrational Properties of Anionic LuGe_n (n = 5–17) Clusters: From Lu-Linked to Lu-Encapsulated Configurations

Abstract

The structural evolution pattern and electronic properties of Lu-doped germanium anion clusters, LuGe n − (n = 5− 17), have been investigated using a global search method combined with a double hybrid density functional theory and by comparing the theoretical PES spectra with the experimental ones. It is found that, for the structural growth patterns, a Lu-linked configuration is preferred for n = 10−14 in which the Lu atom as a linker connects two Ge subclusters and a Lu-encapsulated Ge cage-like motif is preferred for n = 15−17. The simulated PES spectra agree with experimental ones, revealing that the current global minimum structures are the true minima. The properties such as relative stability, charge transfer, highest-energy occupied molecular orbital−lowest-energy unoccupied molecular orbital (HOMO− LUMO) gap, IR, Raman, and ultraviolet−visible (UV−vis) spectra have been evaluated. The results of IR and Raman spectra could provide additional ways to experimentally identify the structure of these clusters. The results of stability, HOMO−LUMO gap, and UV−vis spectra could make the LuGe 16 − cluster the most suitable building block for further development as a potential optoelectronic material.

Structural evolution, photoelectron spectra and vibrational properties of anionic GdGen− (n = 5–18) nanoalloy clusters: a DFT insight

“…Compared to anionic LuGe n − ( n = 5–17) clusters, 11 the AAE curves of LuGe n − and GdGe n − are in parallel as can be seen from Fig. S2 in ESI †.…”

“…(2) Deduced from the earlier reported structures. 11,17,20 The low-lying geometries that come from above calculations were re-optimized by using PBE0 combined with cc-pVTZ-PP 29 and quasi-relativistic ab initio effective core potential def2-TZVP 30,31 basis set for Ge and Gd atoms, respectively. After optimization, vibrational frequency investigations were considered to proof the nature of stationary points.…”

“…9,10 On the other hand, exploring the geometric mutations, electronic structures, photoelectron spectra and vibrational modes of nanoalloy clusters have considerable importance due to the fact that nanoalloy clusters play an incredibly essential role in the shift from molecular to condensed matter, with the ongoing progress and widespread application of nanotechnology. 11…”

“…9,10 On the other hand, exploring the geometric mutations, electronic structures, photoelectron spectra and vibrational modes of nanoalloy clusters have considerable importance due to the fact that nanoalloy clusters play an incredibly essential role in the shi from molecular to condensed matter, with the ongoing progress and widespread application of nanotechnology. 11 Rare earth metals (REMs) have properties such as high magnetic moments and extremely narrow optical transitions. For example, rare earth molecular crystal has extremely narrow optical transitions and long-lived quantum states, which enables it to be used in elds such as quantum communication and quantum processors, thereby opening up optical quantum systems.…”

“…In addition, the stability of Ge clusters can be improved by doping with rare earth elements since pure Ge clusters possessing only sp 3 -hybridized bonding characteristics are unstable. [13][14][15] For instance, ScGe 16 À , 16 LuGe 16 À , 11 and LuGe 17 + (ref. 17 and 18) have been evaluated to be high-symmetry endohedral structures, which give prominence to enhance stability and render them possibly as a building block for new multi-functional nanomaterials.…”