Coulomb exchange interaction between electrons in the atom and structure of complex configurations

Abstract

The Coulomb exchange interaction operator and its matrix elements are represented in a special form, which enables the investigation of groups of terms, caused by this interaction, and the construction of new wavefunction bases. ?he existence of distinct upper and lower groups ofterms due to exchange interaction in configurations "(1-I)-'nlN and n14'i2-Nn(l+ I ) for small numbers of electrons or vacancies N = 1.2 is shown. The separation of groups becomes more pronounced in the two-configuration approximation on taking into account correlations with symmetric exchange of symmetry. In this case a new wavefunction basis is proposed.

Investigation of the cascades in atoms using the global characteristics of spectra

“…It is related with the existence of two level groups caused by the Coulomb exchange interaction -only the levels of the upper group mainly participate in the transitions [96]. The shift of the receptive zone also tends to be positive.…”

Additional selection rule for some emission, photoexcitation and Auger spectra

“…The similar variation of the spectra arising from the open 4d and 4p shells takes place for the Sm isonuclear sequence [4]. Consideration of the average energy of Auger transitions (8) shows that the enhancement of high-energy lines and suppression of low-energy lines are most pronounced at a small number of electrons in the outer shell [6].…”

“…of considered spectra. Some reasons for the preciseness of the HP basis may be pointed out: (a) the main part of the interaction dominating in such configuration only has diagonal matrix elements; (b) in the HP basis some matrix elements connecting such configuration with the other configuration of the same complex vanish [8] (since the corresponding operator, similarly as the Auger transition operator, can be expressed by the operator A (10) (1)). The calculations in intermediate coupling give small intensities of lines that are forbidden by the indicated selection rule from the lower group of levels of excited configuration.…”

High-Frequency Response in Ferroelectric BaSrTiO3 Thin Films Studied by Terahertz Time-Domain Spectroscopy

“…Moreover, the highest contribution of the 4d4f levels in Rh VIII is 34% and only one established level was designated as 4d4f in Rh VIII and Pd IX (table 6) on the basis of the first term of level percentage composition. It is known [9,10] that in the spectrum of transitions of the 4p 6 4d k (4p 6 4d k−1 4f + 4p 5 4d k+1 ) type, a zone of preferential transition probability, the so-called 'emissive zone', exists because of large exchange and configuration interactions. Only the transitions from a narrow range of the highest levels have high transition probability.…”