Stability and Nonadiabatic Effects of the Endohedral Clusters X@Al₁₂ (X = B, C, N, Al, Si, P) with 39, 40, and 41 Valence Electrons

Abstract

Metallic nanoclusters, with one electron or hole difference from closed shell, might end up in a degenerate state undergoing a Jahn–Teller distortion as a result of nonadiabatic effects, which are a manifestation of the electron–vibron coupling. Here, we report a theoretical study on the stability and nonadiabaticity of the neutral and charged endohedral clusters X@Al12 (X = B, C, N, Al, Si, P) around icosahedral symmetry, for 39, 40, and 41 valence electrons. The nonadiabatic effects are evaluated through the Jahn–Teller gain for the distorted cluster and their effect on the calculated electronic density of states is analyzed. For the 40 electron valence systems, we present the full vibrational spectra. Our results are discussed within the framework of the superatom model, and show that not all systems are well described by the spherical jellium model and that nonadiabaticity is better represented by ellipsoidal models. We present a detail discussion of the Al13 –1 electron detachment process and show how, through a comparison with available experimental photoelectron spectroscopy data, the nonadiabaticity can be estimated.

Strong lowering of ionization energy of metallic clusters by organic ligands without changing shell filling

“…All the geometries were optimized without any symmetry constraint. We have considered only endohedral doped Al icosahedral clusters since previous theoretical studies have reported that the endohedral doping is energetically more favorable than the exohedral doping 30 , 31 . The Al 13 and BAl 12 both have 39 valence electrons with electronic configuration of 1S 2 1P 6 1D 10 2S 2 1F 14 2 P 5 .…”

Pseudo Jahn–Teller effect in the decasilanaphthalene molecule: Towards the origin of the buckling in silicene

“…The power of prediction of these methods have been previously tested for the hexasilabenzene molecule [25]. We followed the method developed by Molina et al [29] to estimate the JahnTeller energy gain (EJT). In order to determine the coupling of the ground state with some excited state, singlet to singlet electronic transitions for the first seventy excited states were evaluated for the D 2h Si 10 H 8 cluster using TDDFT with ZORA scalar and all electron TZ2P basis.…”

Bonding and properties of superatoms. Analogs to atoms and molecules and related concepts from superatomic clusters

“…Soto and coworkers evaluated the series of endohedral clusters involving the icosahedral Al 12 cage, of the form X@Al 12 (X = B, C, N, Al, Si, P) leading to 39, 40, and 41 valence electrons, which are one electron or hole clusters related to the closed shell 1S 2 1P 6 1D 10 2S 2 2P 6 Al 13 − superatom. This open‐shell configuration for 39 and 41 electrons, results in a partially filled degenerate state which in turn undergoes a Jahn–Teller distortion with an ellipsoidal departure from the spherical.…”

“…It is important to stress that besides the favorable electronic structure and geometrical shape, further analysis of possible isomers should be carried out to pursue energy minima geometries. [51] Soto and coworkers [52,53] [54] Their results indicate the relevance of keeping the dopant atom lying on the cluster surface, and thus, further efforts in the characterization of cage doped clusters should be pertinent in catalytic application, in addition to endohedral doping.…”