Orbital rearrangement

The active electrons are thus explicitly correlated, while the inactive electrons are not. One expects that the lack of correlation in the inactive subsystem will result in a constant error throughout the potential surface and therefore just uniformly shift the calculated energies relative to fully correlated surfaces. Note that in this model the inactive electrons are still affected by the progress of the reaction, since their orbitals rearrange and optimize at all points of the reaction coordinate. It is simply their mutual correlation that is considered as constant. 

RESONANT ORBITAL REARRANGEMENT DURING F Is IONIZATION OR DECAY PROCESS... 

Within the simplest picture for isolated atoms, ionized and excited states are initial ones for X-ray and Auger transitions. However, in molecules the orbital rearrangement following ionization and electronic excitation occurs in general due to the interaction of an inner-shell hole with the molecular field. This makes structures of the X-ray and Auger spectra complicated. 

FIGURE 3. Ionization, shaking and orbital rearrangement processes of the F ion in a fluoride at the time of Auger electron emissions. 

FIGURE 4. F K X-ray emissions after the orbital rearrangement in a fluoride. 

From the discussions of this chapter, origin of the M line in the F KW Auger spectrum is now well understood, which is the resonant orbital rearrangement, ROR. 

KEY WORDS PIXE, X-ray satellite. Electronic structure. Molecular orbital calculation, DV-Xo, Resonant orbital rearrangement... 

The present author proposed an the approximation method to explain the deviation of the X-ray satellite spectra intensity distributions from those described by eqs.(2),(5),(8) and (10), which we call Resonant Orbital Rearrangement (ROR) [6]. ROR was first used to explain the anomalous intensity distributions in F Ka satellite spectra which are emitted from a series of alkali-fluorides. Here resonance occurs during F Is ionization between the highest occupied molecular orbital (HOMO) in the KT. state and HOMO in the (K L +3s) state corresponding to the lowest unoccupied molecular orbital (LUMO) in the K L state. This leads to a reduction in the K L X-ray satellite intensity and to an increase in the K L X-ray diagram line intensity. Here (K L +3s) denotes the state with one vacancy in K shell and one vacancy in L shell and one electron in a 3s... 

Fig.l2. Resonant Orbital Rearrangement between the HOMO in the K L state and the HOMO in the (K L +3s) state for an element with Z=9 or less. This is a kind of excitation of an electron from the HOMO to the LUMO during Is ionization. 

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