2p-core ionization energies

SHELL EFFECTS AND HOMOTHETIC EXPRESSIONS FOR ELECTRON RELAXATION AND OTHER CORRECTIONS TO 2p-CORE IONIZATION ENERGIES AND SPIN-ORBIT SPLITTING FOR ATOMS FROM Cl TO Ba... 

In this paper, we shall present a procedure for evaluating electron relaxation, inner-core correlation, and Breit, qed, and nuc corrections to 2p-core ionization energies and spin-orbit splitting in molecular systems, from tabulated results on atoms from Cl to Ba, excluding transition elements. 

In Table 1 we have gathered measured values of 2p-core ionization energies and spin-orbit splitting of atoms from A1 through Ba [25]. 

Table 1. For elements from A1 (Z = 13) to Ba (Z = 56), measured 2p-core ionization energies [25b] and resulting spin-orbit splitting A (in eV). Energy values are given as being accurate to within 0.3-0.7 eV.

Figure 1. Experimental variations of 2p-core ionization energies (in eV) for atoms from A1(Z = 13) to Ba(Z = 56). Upper left. 2p /2 and 2p3/2 energies lower left, their weighted-average second-order discrete derivative, as functions of Z upper right spin-orbit splitting between the 2pi/2 and 2p3/2 levels lower right, its second derivative, as functions of Z. On the derivative diagrams shell effects appear about fully filled and half-filled shells and near filling irregularities of the transition elements.

The computations of 2p-core ionization energies were performed using a pattern similar to that used for Is- and 2s-core ionization energies [9]. Here again we have used Bruneau s multiconfiguration Dirac-Fock (MCDF) ab initio program [26-28], which is based on a numerical resolution of the Dirac equation corrected for Breit terms, vacuum polarization, and radiative (qed) contributions, and nuclear size and motion (nuc) effects. 

Obviously for each type of core ionization (C Is, 0 Is, P 2p, etc.), there is a different value of Az- Carbon Is binding energies and the corresponding calculated Ac values for some gaseous carbon compounds are given in Table 2. It can be seen that the various Ac values are fairly constant ... 

A second technique is X-ray PE spectroscopy and this provides information about core ionizations. Electron binding energies of the sulfur atoms in 1,3,5-trithiane and its oxides have been reported and differences in the binding energy of the 2p electrons indicate that there is partial charge transfer from the sulfide sulfur to the rf-orbitals of the oxidized sulfur atoms (72CC450). 

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