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Multielectron coincidence spectroscopy has been used to study core 4/ valence 5d, 6s double photoionization of atomic mercury. Multiconfiguration Dirac-Fock calculations were performed to calculate the energies and to estimate the single-photon intensities of the 4f13(5d96s² + 5d106s¹) double-ionized states of atomic mercury. Reasonable agreement between the measured and simulated spectra is found if the relaxation effects of the bound-state density is taken into account in the computation of the photoionization amplitudes. [ABSTRACT FROM AUTHOR]

Multielectron coincidence spectroscopy has been used to study multiple ionization of atomic mercury. The binding energies of triply and quadruply ionized states of Hg have been determined from three- and fourfold - electron coincidences. Relativistic ab initio theory has been used to calculate the state energies and predict the experimental findings. [ABSTRACT FROM AUTHOR]

Single and double Auger processes following ionization of 4 f and 5p inner shells have been studied using multielectron coincidence spectroscopy. Coincidence technique enables us to resolve state by state all single and double Auger paths with a resolution better than the lifetime broadening. Drastic step-to-step decay lifetime changes are observed and reported as Coster-Kronig transition takes place either in the first (5p) or in the second (4f) step of the Auger cascade. Relativistic ab initio theory has been used to predict and interpret the experimental observations. [ABSTRACT FROM AUTHOR]

The photoelectron-photoion-photoion coincidence method is used to measure the photodissociation of doubly charged D-ribose (C5H10O5), the RNA sugar molecules, and 2-deoxy-D-ribose (C5H10O4), the DNA sugar molecules, following normal Auger decay after initial C 1s and O 1s core ionizations. The fragment identification is facilitated by measuring isotopically labeled D-ribose, such as D-ribose deuterated at C(1), and with 13C at the C(5) position. Ab initio quantum chemistry calculations are used to gain further insight into the abundant appearance of the CHO+ fragment. [ABSTRACT FROM AUTHOR]

We have studied photoionization in the inner valence 3i subshell of and the spectroscopic properties of the two 3s-1 (¹S) and (³S) resulting states. Similar to the Rb and Cs cases, the lifetime widths of the (¹S) and (³S) states are found to be markedly different, due to the electron correlation effects. The main part of the study deals with the subsequent Auger decay of the 3s-1 states, which have the particularity to involve low energy (~5 eV) Auger electrons. A magnetic bottle spectrometer with a multicoincidence technique has been used to observe and filter the Auger spectra with respect to the K2+ final state. The evolution of these Auger spectra has been investigated near the ionization threshold. They show strong post-collision interaction (PCI) effects, which are well reproduced by semiclassical and eikonal models. They reveal the importance of the photoelectron-Auger-electron interaction associated with these low energy Auger electrons. [ABSTRACT FROM AUTHOR]

In this work, we consider the dissipative dynamics of a quantum Brownian magneto-oscillator in contact with different types of environment at zero temperature as well as at high temperatures. We derive closed-form expressions of decay rate and heating rate for the magneto-oscillator in contact with Ohmic, sub-Ohmic, and super-Ohmic environments with non-Markovian characteristics. The present study is useful in determining the relationship between the thermalization dynamics of a magneto-oscillator and different forms of environmental spectrum and external magnetic field. Although our study is limited to the short-time (Non-Markovian) and long-time (Markovian) regimes, it manifests that one can actually tune the effective coupling of the system reservoir either by tuning oscillator frequency through reservoir engineering techniques or changing external magnetic field. Thus the present work establishes the essential role of non-Markovian dissipation and the crucial role of magnetic field in the environment induced decoherence and decay processes of the dissipative magneto-oscillator. [ABSTRACT FROM AUTHOR]

The 3p photoionization and subsequent Auger decay of initially neutral atomic germanium is studied both experimentally and theoretically. The binding energies and relative intensities of the 3p photoelectron spectrum are given. The M2,3 M3,4 M3,4 and M2,3 M3,4 N Auger electron spectrum leading to doubly ionized final states is presented. The photoelectron and Auger electron spectra were interpreted using multiconfiguration Dirac-Fock calculations that provided the identification for the main spectral features. [ABSTRACT FROM AUTHOR]

The VUV-induced photofragmentation of As4 clusters was studied using photoelectron-photoion-coincidence (PEPICO) spectroscopy. The fragmentation pathways subsequent to outer and inner valence photoionization and resonant photoexcitation were studied by examining the cationic production as a function of electron energy. In addition, regular photoelectron spectroscopy and partial ion yield absorption spectroscopy were employed. In order to enhance the weak signal from the inner valence states, resonant core 3d excitation was used in the PEPICO experiment. The fragmentation pathways were inspected with the aid of ab initio and thermochemical calculations. The many-electron effects were found to play a major role in the observed inner valence structure and resulting photofragmentation. [ABSTRACT FROM AUTHOR]

The electronic structure and fragmentation of the hydrofluorocarbon compound 1,1,1,2-tetrafluoroethane (CF3 -CH2F) were studied using spectroscopical methods and quantum chemical calculations. Valence photoelectron spectra and the ionic fragmentation products were recorded with synchrotron radiation in the vacuum ultraviolet (VUV) region. The geometric and electronic structures of the CF3-CH2F molecule were calculated using the complete active space perturbation theory of second order. The calculated vertical ionization energies were used to interpret the experimental photoelectron spectrum. VUV photodissociation of the sample molecule was studied with photoelectron-photoion coincidence spectroscopy. Coincident ion yields are shown for several cations as a function of electron binding energy. The experimental data are discussed in comparison with theory and previous work. [ABSTRACT FROM AUTHOR]

Experimental and theoretical study of the 3d photoionization and subsequent Auger decay of initially neutral atomic germanium is presented. The features of the high-resolution photoelectron and Auger electron spectra are interpreted with the aid of multiconfiguration calculations. The binding energies and relative cross sections of the 3d ionized fine-structure states of Ge are given. The complete M4.5N N Auger electron spectrum to doubly ionized final states of the Ge ion is interpreted and discussed. [ABSTRACT FROM AUTHOR]

The valence photoionization and resonant Auger decay at 4d resonances below the 4d ionization threshold in Sb4 clusters have been studied experimentally by means of photoelectron spectroscopy. The 4d absorption spectrum in the photon energy region from 30 to 36 eV has been recorded using the constant ionic state (CIS) partial electron yield (PEY), and the CIS spectra for various ionic states are presented. The photoelectron spectra at various resonant positions are recorded, and the results and their interpretation are presented. The findings provide experimental proof of the previous assignment of the various structures of the inner valence photoelectron spectrum. [ABSTRACT FROM AUTHOR]

Xe 1s photoelectron spectra were measured at SPring-8, Japan. The core-hole lifetime broadening was found to be 9.6 eV, yielding a lifetime of ~68 as. The amount of radiative versus nonradiative decay was assessed by recording Auger LMM spectra below and above the K edge. Below the K edge, L vacancies are produced only by direct photoionization, while above the K edge some of these vacancies are mainly produced by KL emission following 1s photoionization. Due to the dipole selection rule for x-ray emission, the dominant role of the KL relaxation process is rather directly observed. [ABSTRACT FROM AUTHOR]

The M4,5N2,3N2,3 and M4,5N1N2,3 Auger decay of atomic Rb have been studied by using photoelectron-Auger electron coincidence measurements that enable initial ionic state selected Auger spectroscopy. The Auger spectra in the present study are separated by the total angular momentum j of the 3 d hole and the orbital of the valence electron n l after photoionization. It is shown that the technique allows isolating overlapping features and the study of otherwise unobservable spectral details, from which the presence of shake-down transitions during normal Auger decay is demonstrated experimentally. The technique allows also probing the effects of initial state parity and electron correlation in Auger electron spectroscopy. The observed spectral features are interpreted with theoretical predictions obtained from configuration interaction Dirac-Fock approach. [ABSTRACT FROM AUTHOR]

Photoinduced reformation of chemical bonds is investigated in the CH3Cl molecule experimentally and computationally. The observation of stable HCl+ fragment formation after resonant Cl 2p photoexcitation is confirmed by an electron-ion coincidence experiment, and its possible creation mechanism is reported. We attribute the formation of HCl+ to specific final states populated by the resonant Auger decay. Quantum chemical computations support this attribution and suggest that in at least one of those states the system is placed on a potential energy surface which favors creation of HCl+ by moving one hydrogen atom to a closer proximity of the chlorine atom. This work demonstrates the effect of targeted core-shell excitation on the chemical bond breaking and reformation process, often called photoinduced chemistry. [ABSTRACT FROM AUTHOR]

A correction to the article "5p Photoemission From Laser-Excited Cesium Atoms" that was published in the December 27, 2011 issue is presented.