Electric properties of hydrogen iodide: Reexamination of correlation and relativistic effects

The electric dipole moment and the static dipole polarizability of the hydrogen iodide molecule were studied using sophisticated correlated and relativistic methods. Both scalar and spin–orbit relativistic effects were carefully accounted for. We conclude that the large differences between the theoretical and experimental dipole moment, the dipole moment derivative and the polarizability cannot be reconciled by improved account of electron correlation and relativistic effects. The most striking difference between theory and experiment is observed for the polarizability anisotropy. We believe that experimental data, namely the experimental dipole moment (the most recent value is 0.176 au as compared to our best theoretical estimate, 0.154±0.003 au), the parallel polarizability (44.4 and 38.47±0.05 au) and the anisotropy (11.4 and 2.33±0.05 au) must be inaccurate. Experimental and theoretical perpendicular polarizability components (33.0 and 36.14±0.05 au,) and the mean polarizability (36.8 and 36.92±0.05 au) agree better. Our vibrationally corrected relativistic CCSD(T) results represent the most sophisticated predictions of electric properties of HI obtained so far.Contribution to the Björn Roos Honorary Issue     

Two-quasiparticle bands in neutron-rich nuclei

The large multi-detector arrays such as EUROBALL and GAMMASPHERE have made possible the study of the spectroscopy of neutron-rich nuclei through the observation of discrete, prompt -rays emitted following fission. Most of the information obtained has concerned yrast states and collective excitations. In the present work, a search has been made for excited bands based upon two-quasiparticle intrinsic structures. Such bands have been found in several even-even nuclei from ⁹⁶Sr to ¹¹²Pd. Careful analysis of triple-coincidence spectra has been performed in order to determine branching ratios within the bands. These branching ratios are then used to establish the magnetic properties of the intrinsic structure, permitting, in most cases, the determination of which Nilsson orbits (and whether they are neutron or proton states) are contributing to the excitation. Some example results from this search are presented.Received: 1 November 2002, Published online: 2 March 2004PACS: 23.20.Lv transitions and level energies - 21.60.Ev Collective models - 27.60. + j      

Ultrahigh-resolution spectrometer for the 5-microm wavelength region

We present an ultrahigh-resolution saturation spectrometer based on a line-tunable carbon monoxide laser near 60 THz (lambda = 5 microm). A spectral resolution of 14 kHz (Dnu/nu = 2.3 x 10(-10)) for CO fundamental-band transitions was achieved, which improves on earlier results by one order of magnitude. A frequency-locking scheme using tunable microwave sidebands provides tunability and absolute frequency control of the CO laser on the kilohertz. Transit-time broadening and pressure broadening of the observed transitions are significantly reduced by use of expanded laser beams in a 24-m absorption cell at pressures down to 0.0 1Pa. The new spectrometer is suitable for the study of saturation line shapes and the development of a new generation of frequency standards in the 60-THz region.     

Coupling of microdialysis with capillary electrophoresis: a new approach to the study of drug transfer between two compartments of the body in freely moving rats.

A method was developed for the analysis of molecular species of 1,2-diacyl-sn-3-glycerophosphocholine and 1,2-diacyl-sn-3-glycerolphosphoethanolamine from natural sources. The method involves enzymatic hydrolysis of the sn-3 position of the glycerophospholipids, acetylation of the newly liberated hydroxyl group and high-temperature gas chromatography of the 1,2-diacyl-3-acetyl-sn-glycerols. Both the enzymatic hydrolysis and the gas chromatographic separation were optimized with chemometric methods.     

Evidence for shape coexistence in186Pt

High-spin states in¹⁸⁶Pt have been populated by the¹⁸⁸Os (α, 6n) reaction and were investigated with the OSIRIS spectrometer. A shape coexistence at high spins was established in the nucleus¹⁸⁶Pt, which lies on the border between light prolate and heavy oblate Pt nuclei. Two bands corresponding to predominantly prolate shapes and one band of predominantly oblate shape have been observed. For prolate shapes a (π h _9/2)² alignment and for oblate shapesa (vi _13/2)² alignment has been found.     

A classification of quantum Hall fluids

In this paper, the key ideas of characterizing universality classes of dissipationfree (incompressible) quantum Hall fluids by mathematical objects called quantum Hall lattices are reviewed. Many general theorems about the classification of quantum Hall lattices are stated and their physical implications are discussed. Physically relevant subclasses of quantum Hall lattices are defined and completely classified. The results are carefully compared with experimental data and also with other theoretical schemes (the hierarchy schemes). Several proposals for new experiments are made which could help to settle interesting issues in the theory of the (fractional) quantum Hall effect and thus would lead to a deeper understanding of this remarkable effect.     

Study of band structures and crossings in179Re

High-spin states in¹⁷⁹Re have been populated by the¹⁶⁵Ho(¹⁸O, 4n) and¹⁷⁰Er(¹⁴N,5n) reactions. A level scheme is constructed from the studies ofγγ-coincidences using anti-Compton spectrometer arrays. The previously known 5/2⁺[402], 1/2^? [541] and 9/2^? [514] bands have been extended to 35/2⁺, 45/2^? and 39/2^?, respectively. In addition a 1/2⁺ [660] band, a three-quasiparticle band and two isomers were established. Furthermore several level sequences were identified decaying into the 5/2⁺ [402] and 1/2^? [541] bands. This allowed to determine the excitation energy of the 9/2^? member of the latter band. The band crossing features of the bands have been explained as the rotation alignment of ani _13/2 quasineutron pair taking into account shape changes.     

s-f exchange interaction in metallic GdxY1−xS and GdxLa1−xS

We compare ESR spectra of insulating EuS with those of metallic GdS. ESR investigations of the diluted metallic compounds Gd_xY_1?xS and Gd_xLa_1?xS prove the existence of an exchange interaction between conduction electrons and localized 4f moments in these sulphides. Since a bottleneck occurs, we attribute this interaction to conduction electrons with s character at the Fermi level.