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Hyperfine Structure (hyperfine + structure)

Distribution by Scientific Domains

Physics and Astronomy	50%
Chemistry	50%

Selected Abstracts

ChemInform Abstract: Oxygen-17 Hyperfine Structures in the Pure Rotational Spectra of SrO, SnO, BaO, HfO and ThO.

CHEMINFORM, Issue 5 2008
Christopher T. Dewberry
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Hyperfine structure of hydrogen and geonium

LASER PHYSICS LETTERS, Issue 2 2004
A.V. Andreev
Abstract The self-consistent theory of hyperfine atomic structure is developed. The theory is based on Lorentz and gauge invariant equation for action of spin 1/2 particle. The specific feature of proposed equation for action (or Lagrangian) is that it is enable to introduce the three material constants: mass m0, charge q, and magneton (i.e. magnitude of magnetic moment) ,. The analytically tractable solutions of the wave equation for the electron motion in Coulomb field and electron motion in uniform magnetic field are found. In both cases the calculated spectra include the hyperfine splitting that is agreed well with the experimentally observed spectra. The calculated frequencies of 8(12)d3/2 , 8(12)d5/2 transitions in hydrogen atom are compared with the results of experimental measurements by the highprecision spectroscopy methods. It is shown that the results of calculations are in good agreement with the experimentally measured data. (© 2004 by HMS Consultants. Inc. Published exclusively by WILEY-VCH Verlag GmbH & Co.KGaA) [source]

Two-step method for precise calculation of core properties in molecules

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 2 2005
A. V. Titov
Abstract Precise calculations of core properties in heavy-atom systems that are described by the operators heavily concentrated in atomic cores, such as hyperfine structure and P,T-parity nonconservation effects, require accounting for relativistic effects. Unfortunately, four-component calculation of molecules containing heavy elements is very consuming already at the stages of calculation and transformation of two-electron integrals with a basis set of four-component spinors. In turn, the relativistic effective core potential (RECP) calculations of valence (spectroscopic, chemical, etc.) properties of molecules are very popular, because the RECP method allows one to treat quite satisfactorily the correlation and relativistic effects for the valence electrons of a molecule and to reduce significantly the computational efforts. The valence molecular spinors are usually smoothed in atomic cores, and, as a result, direct calculation of electronic densities near heavy nuclei is impossible. In this paper, the methods of nonvariational and variational one-center restoration of correct shapes of four-component spinors in atomic cores after a two-component RECP calculation of a molecule are discussed. Their efficiency is illustrated in correlation calculations of hyperfine structure and parity nonconservation effects in heavy-atom molecules YbF, BaF, TlF, and PbO. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [source]

Photon echo in ruby doped only by 53Cr isotope ions

LASER PHYSICS LETTERS, Issue 8 2008
V.V. Samartsev
Abstract The signals of photon echo (PE) are investigated firstly in a ruby crystal doped only by the 53Cr isotope ions in a concentration of 0.03 , 0,05 wt%. The optical experiments were performed in backward regime at the wavelength of 693.4 nm both with a low magnetic field (200 G) and without it. Since the 53Cr isotope ions have hyperfine structure of levels the special attention was paid to the study of the stimulated photon echo and primarily to the investigation of its decay kinetics. It is established that this decay has a form which is typical to the signals of longlived PE. But in contrast to the long-lived PE the decay time in our case is less than the lifetime of the excited 2E () state. The signals of primary photon echo and stimulated photon echo at a low longitudinal magnetic field and their decay curves are investigated. We observed the beats of temporal shape of these signals with a period of several tens of nanoseconds. Theoretical analysis shows that they are due to the hyperfine interaction of valence electrons of 53Cr isotope ions with their own nuclei. The obtained decay curves allow us to estimate the phase relaxation time at the presence of a magnetic field. It proves to be equal to 98 ns. The spectrum of stimulated photon echo signal in the doped ruby exposed to a magnetic field is measured. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Electron paramagnetic resonance line shape investigation of the 29Si hyperfine doublet of the E,, center in a-SiO2

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007
Gianpiero Buscarino
Abstract We report an experimental study by electron paramagnetic resonance (EPR) spectroscopy of the E,, center and of its hyperfine structure, consisting in a pair of lines split by 42 mT. Our results show that two types of E,, centers can be distinguished on the basis of the EPR line shapes of their main resonance line and hyperfine structure. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Carbon Dioxide Activation by Surface Excess Electrons: An EPR Study of the CO2, Radical Ion Adsorbed on the Surface of MgO

CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2007
Mario Chiesa Dr.
Abstract The CO2, radical anion has been generated at the surface of MgO by direct electron transfer from surface trapped excess electrons and characterized by electron paramagnetic resonance spectroscopy. Both 13C and 17O hyperfine structures have been resolved for the first time, leading to a detailed mapping of the unpaired electron spin density distribution over the entire radical anion. The magnetic equivalence of the two O nuclei has been ascertained allowing a side-on adsorption structure at low-coordinate Mg2+ ions to be proposed for the surface stabilized radical. [source]