Photoionization closed shell atom

Closed-shell atoms are considered here, because in open-shell systems the photoionization process is generally determined by more than three matrix elements (five parameters). 

Within the dipole approximation (jphoton = 1) and for the example of photoionizing an wp-electron from a closed-shell atom (J = 0), the photoelectron angular momentum is either t = 0 or 2 and, hence,... 

This method has been successfully applied to the photoionization of Hg and Xe [103,101] as well as to the evaluation of the polarizabilities of heavy closed-shell atoms [104] (using a direct time-dependent extension of the LDA for the xc-functional). A concept to deal with excited states in the framework of RDFT has been put forward by Nagy [105]. The derivation and first applications of relativistic extended Thomas-Fermi models may be found in Refs.[106-112]. Furthermore, an RDFT approach to meson field theory for hadronic matter (quantum hadrodynamics) [113] has been established by Speicher et al. [114]. This hadronic RDFT has been successfully applied to the description of nuclear ground states both within the extended Thomas-Fermi model [115-118] and within the KS scheme [119-121]. A corresponding formalism for finite temperature is also available [122,123]. 

Here hco = In[j + e, where e refers to photoelectron energy and I ij is the binding energy of the nly-electron in the atom. Performing the summation in (33.9) over j and neglecting the dependence of e on j, we arrive at the following expression for total photoionization cross-section of the closed shell ... 

Work on energy distributions in double photoionization of complex atoms has so far touched only closed-shell species, the rare gases, mercury, and cadmium. Results are discussed in the following sections according to the energy regime covered. 

For larger clusters much spectroscopic detail is lost, but measurements of the photoionization thresholds provide information concerning cluster ionization potentials. Sodium clusters show a relatively smooth decrease in ionization potential from 5.1 eV for the atom to 3.5 eV for the 14-atom cluster. This is still significantly above the 1.6-eV work function of bulk sodium. For the smaller clusters the odd sizes have a lower ionization potential than the neighboring even-sized clusters because of effects due to open versus closed shell configurations. Recently measurements have been made of the ionization potential of iron clusters up to 25 atoms. In this experiment the ionization potentials were bracketed by the use of various ionizing lasers. There is a decrease in the ionization potential from 7.870 eV for an iron atom to the 4.4-eV work function of the bulk metal, but the trend is by no means linear. Thus, the ionization potential of Fea is about 5.9 eV, while those of Fes and Fe4 are above 6.42 eV. Clusters in the range of 9-12 atoms have ionization potentials below... 

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