Photoemission from hybrid states of Cl@C₆₀ before and after a stabilizing charge transfer

Abstract

Photoionization calculations of the endofullerene molecule Cl@C60 with an open-shell chlorine atom are performed in the time-dependent local density approximation (TDLDA) based on a spherical jellium model. Cross sections for atom-fullerene hybrid photoemission studied show the effects of the hybridization symmetry, the giant plasmon and the molecular cavity. Comparisons with the results of Ar@C60 provide insights in the role of a shell-closing electron and its influence on the dynamics. The results for Cl@C60 are further compared with those of a more stable, lower energy configuration that results after a C60 electron transfers to Cl forming Cl − @C60 + . This comparison reveals noticeable differences in the ionization properties of the antibonding hybrid state while the bonding hybrid remains nearly unaltered showing a magnification covering the entire giant plasmon energy range.

Spin-Polarized Photoelectron Fluxes from Fullerene Anions

“…For C − 60 , the resonance oscillations in σ 2p→s and σ 2p→d were first uncovered in [4] and re-discovered in [5]. They are similar in nature to resonances that have been extensively scrutinized in photoionization of the A atom of A@C 60 endohedral fullerenes for some time now, see, e.g., [8,11,12,14,[18][19][20][21][22][23][24] (and references therein). The resonances are due to the interference of the photoelectron waves scattered off the inner and outer walls of the C 60 cage.…”

Electronic structure and dynamics of confined atoms

“…The aforementioned Puska and Nieminen's [40] model jellium potential (V PN ) accounts for this coupling by employing a self-consistent field of all the electrons in a local-density approximation (LDA). Ground state calculations of A@C 60 using this model [21,43,46,[57][58][59] showed significant hybridization effects between fullerene and atomic electrons. The Xe@C 60 valance orbitals have been studied from the perspective of hybridization [21].…”

“…On the other hand, it was found [21] that the Xe 5s state interacts predominantly with the lowest angular momentum level 2s of empty C 60 π band, leading to about 50-50 mixing. Similarly, it has been found that the Zn 3d subshell exhibits strong hybridization with 4d subshell of C 60 in Zn@C 60 and the Ar 3p subshell hybridizes with C 60 2p levels in Ar@C 60 [43,59]. The hybridization of atomic orbitals significantly affects the dynamics of the system.…”

“…The initial and final state wave functions of the delocalized (valence) electrons of the C 60 molecule plus the electrons of the confined atom are obtained, and both structure and photoionization are obtained using such a jellium potential using a variety of methods. This model has been successfully employed in a number of photoionization calculations by Chakraborty et al [21,43,46,[57][58][59], showing significant effects of the interaction between fullerene and atomic electrons with hybridization of atomic and shell orbitals in the initial states and interchannel coupling between atom and shell photoionization channels in the final states.…”

“…A number of simple spherically symmetric model potentials, which treat the effects of the fullerene on the confined atom, have been employed to simulate the endohedral environment [26,27]. Theoretical methods involving both the atomic and the fullerene valence electrons within a spherical jellium potential have also been developed and successfully applied to a range of confined systems [21,43,46,[57][58][59]. These studies have been useful in identifying specific features in a spectrum that belong to the confined atom, to the fullerene itself, and also the features resulting from the coupling of the atomic and fullerene ionization channels.…”