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[en] Using a diagrammatic superoperator formalism we calculate optical signals at molecular junctions where a single molecule is coupled to two metal leads which are held at different chemical potentials. The molecule starts in a nonequilibrium steady state whereby it continuously exchanges electrons with the leads with a constant electron flux. Expressions for frequency domain optical signals measured in response to continuous laser fields are derived by expanding the molecular correlation functions in terms of its many-body states. The nonunitary evolution of molecular states is described by the quantum master equation

[en] We study the decay of a helium/neon dimer after ionization and simultaneous excitation of either the neon or the helium atom using Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS). We find that, depending on the decaying state, either direct Interatomic Coulombic Decay (ICD) (i.e. mediated by a virtual photon exchange), exchange ICD (mediated by electron exchange) or radiative charge transfer occurs. The corresponding channels are identified.

[en] Electron exchange between a metal or semiconducting electrode and a solvated reactant is calculated by Green-function techniques. In the wide band approximation the time development of a system prepared in a definite electronic state can be calculated exactly. The results are valid for all coupling strengths, and are applied both to photoexcited and to thermally-induced transfer

[en] The problem of charge exchange between a negative hydrogen ion and nanosystems (thin metal films and island films) is considered. Quantum-mechanical calculations show that the effectiveness of charge exchange is determined by the ion-surface distance and the structure of discrete electron energy levels inside the film. In turn, the structure of the discrete levels depends on the film’s geometric dimensions. The characteristics of charge exchange (the effectiveness of the electron transfer, the probability of charge exchange, the propagation velocity, and the average coordinate of the electron’s position inside the film) are calculated via solution of the nonstationary Schrödinger equation. It is shown that these quantities can also be approximated by a simple linear model of electron propagation.

[en] The use of spin-polarized particles in atomic collision experiments may allow to study specific details of the reaction. In case of (at least) two active electrons, a spin-depolarisation may result from the exchange of electrons. The effect depends on the electron-electron interaction during the collision. Electron exchange is discussed and a model calculation is performed. (orig.)

[en] We give an organized derivation of the Wigner–Witmer correlation rules in the case when a diatomic term is built by like atoms in the same term. What relates the inversion symmetry with the spin multiplicity is apparently shown to be the symmetric property for N-electron exchange, which means the exchange of all electrons of one atom for those of the other atom. We simplified the derivation, discussing the transformation properties of the total electronic state, the spin part and the orbital part, separately. Furthermore, the numbers of constructed terms are summarized in simple tables. (paper)

[en] Density-functional electronic-structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state α phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic antiferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functional. The 13 independent elastic constants, for the monoclinic α-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from recent resonant ultrasound spectroscopy for a cast sample is made

[en] A comparatively simple interpretation of the method of Firsov is used to calculate symmetric resonant charge transfer cross sections for the first 20 (nontransition) elements H through Ca in the range of low and intermediate collision velocities (≤1.0 x 10⁸ cm/s). The results obtained show good agreement with corresponding experimental data and with the theoretical results of Sakabe and Izawa. Discrepancies between the two sets of theoretical data are discussed

No abstract available