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Atomic Data (atomic + data)
Selected AbstractsSpontaneous radiative decay rates in Ga-like ionsINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4 2008E. Charro Abstract The analysis of forbidden lines, such as E2 and M1, in the atomic spectra emitted by certain ions is important for the study of the plasma in astrophysical objects and fusion devices. Atomic data, such as wavelengths and transition rates for 4p3/2 , 4p1/2 emission lines in the gallium sequence have been calculated with the Relativistic Quantum Defect Orbital (RQDO) method. The present results are tested by comparison with other theoretical values available in the literature. The regularity of the transition intensities along the isoelectronic sequence for both (E2 and M1) lines, as well as their relative magnitude, are also analyzed. M1 transitions were found to dominate by at least a factor of ten times, being in many cases bigger that this. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source] Density Diagnostic Using Stark Broadening of He I Spectral Line Emission from Rydberg LevelsCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7-9 2006M. Koubiti Abstract Neutral helium line spectra of the diffuse series observed under recombining plasma conditions, are used for electron density diagnostics. The method is similar to that using high members of the Balmer series of hydrogen or its isotopes. It is based on the comparison of experimental line spectra to calculated Stark profiles obtained with the Stark line shape code PPP. Among the required atomic data, the dipole reduced matrix elements have been calculated using a hydrogenic approximation. A good agreement was found between the behaviors of the Einstein coefficients calculated using this approximation and the available corresponding values found in the literature. It is demonstrated here through its application to JET data that for relatively dense plasmas this method gives promising results which are consistent with other measurements. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Development of new pseudopotential methods: Improved model core potentials for the first-row transition metalsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 9 2003Christopher C. Lovallo Abstract We have recently developed new nonrelativistic and scalar-relativistic pseudopotentials for the first-row transition metal and several main-group elements. These improved Model Core Potentials were tested on a variety of transition metal complexes to determine their accuracy in reproducing electronic structures, bond lengths, and harmonic vibrational frequencies with respect to both all-electron reference data as well as experimental data. The new potentials are also compared with the previous model core potentials available for the first-row transition metals. The new potentials do a superior job at reproducing atomic data, reproduce molecular data as well as the previous version, and in conjunction with new main-group pseudopotentials that have L-shell structure of the valence basis set, they are slightly faster. © 2003 Wiley Periodicals, Inc. J Comput Chem 9: 1009,1015, 2003 [source] Astrophysical laser operating in the O i 8446-Å line in the Weigelt blobs of , CarinaeMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005S. Johansson ABSTRACT Within the framework of a simple model of photophysical processes in the Weigelt blobs in the vicinity of the luminous blue variable (LBV) star , Carinae, we explain the presence of the fluorescent ,O i, 8446-Å and forbidden [O i] 6300-Å lines as well as the absence of the allowed O i 7774-Å line in spectra recorded with the Hubble Space Telescope (HST)/STIS instrument (Gull et al.). From atomic data and estimated stellar parameters we demonstrate that there is a population inversion and stimulated emission in the 3p 3P,3s 3S transition ,8446 due to photoexcitation by accidental resonance (PAR) by H Ly, radiation. [source] Elemental abundance analyses with DAO spectrograms: XXXI.ASTRONOMISCHE NACHRICHTEN, Issue 1 200841 Cyg (F5 Ib-II), Her (F2 II), The early F supergiants Abstract This series of high quality elemental abundance analyses of mostly Main Sequence normal and peculiar B, A, and F stars defines their properties and provides data for the comparison with analyses of somewhat similar stars and with theoretical predictions. Most use high dispersion and high S/N (, 200) spectrograms obtained with CCD detectors at the long camera of the 1.22-m Dominion Astrophysical Observatory telescope's coudé spectrograph. Here we expand the range of stars examined to include two relatively quiescent F supergiants. , Her (F2 II) and 41 Cyg (F5 Ib-II) are analyzed as consistently as possible with previous studies. These LTE fine analyses use the ATLAS9 and the WIDTH9 programs of R. L. Kurucz. High signal-to-noise spectrograms and high quality atomic data were employed. The derived values of these photometrically constant stars are somewhat different with the abundances of , Her being somewhat metal-poor and those of 41 Cyg being crudely solar-like. Our analyses indicate that the basic results of Luck & Wepfer (1995) who also studied , Her and 41 Cyg are not likely to be significantly changed by new studies of all their stars. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||