Ionization energies of cesium and cesium oxide clusters

Abstract

The vertical ionization potentials of 7 cesium and 86 oxidized cesium clusters were determined using the technique of photoionization mass spectrometry. The spectra were obtained using a tunable cw dye laser for clusters in a mass range 1 to 2024 amu. The vertical ionization potentials (IP) are presented as a function of size and composition. The ionization energies of cesium clusters, Cs,, decrease with cluster size. Unusually low IP were observed for the enneamer, Cs9, and for the cesium monoxide Csl xO. With increasing oxidation of the cesium metal clusters the IP decreases (suboxides) reaches a minimum at Cs(Cs20). and then increases (superoxides).

Discovery of Magnetic Superatoms and Assessment of van der Waals Dispersion Effects in Csn Clusters

“…Despite the substantial interest brought about the light alkali metal clusters, the number of studies devoted to the heavier Cs n clusters is comparatively scarce. Martin and co-workers reported experimental abundances, ionization energies, and photoabsorption spectra of small pure cesium clusters and also of bigger cesium clusters doped with oxygen or with SO 2 impurities. − They observed ionization energy maxima when the number of valence electrons N e equals 8, 18, 34, 58, 92, ..., in agreement with jellium model predictions, although clusters with 20 and 40 electrons did not show any significant feature. The jellium picture is appropriate even when ionic impurities are present, the main effect of each oxygen impurity being simply a reduction in the number of delocalized electrons.…”

The repopulation of electronic states upon vibrational excitation of niobium carbide clusters

“…(7) and Ref. 35 it directly follows that, even with the same coupling parameter, a system that has a higher number of vibrational modes will have broader transition bands.…”

“…In our final model we use the information about the Kohn-Sham orbitals for a cluster obtained from the DFT calculations in combination with the Fermi-Dirac distribution to determine the population of the electronic density of states, as successfully applied for metallic clusters 16 . Inspired by a model of two displaced harmonic oscillators 35,36 , we further assume that transitions from each populated electronic level E i can be simulated by a Gaussian function dubbed transition band. The maximum of the transition band, i.e.…”

“…where M is the number of the vibrational degrees of freedom of a cluster, and a is a coupling parameter characterizing the displacement between the harmonic oscillators for the ionic and ground states 35 , taken to be the same for each vibrational mode of the cluster. This appears to be a reasonable approximation, as the width σ of the transition band with fixed a now only depends on T .…”

Theoretical prediction for the structures of gas phase lithium oxide clusters: (Li2O)n (n = 1–8)

“…At present, many advances have been done in understanding of metallic and semiconductor clusters, the study of metal‐oxide clusters plays a fundamental role in many physical and chemical processes. In recent years, some studies have been done on metal‐oxide clusters, such as magnesium‐oxide (MgO),2–6 calcium‐oxide (CaO),7, 8 barium‐oxide (BaO),9–12 cesium‐oxide (Cs 2 O),13, 14 silicon‐oxide (Si 2 O),15–19 titanium‐oxide (Ti 2 O),16, 20–22 zirconia (ZrO 2 ),20, 23–25 lithium‐oxide (LiO),26–29 and so forth. In particular, small clusters of lithium‐oxide can attract more interest.…”