Investigations of hyperfine structure and isotope shift predictions in Hf II

Abstract

ABSTRACT:The fine structure of the even-parity low configurations of singly ionized hafnium has been reanalyzed by simultaneous parameterization of the one-and two-body interactions for the model space (5d þ 6s) 3 . Using the calculated eigenfunctions, the magnetic-dipole A hyperfine constants for the whole 37 existing levels of the model space were predicted and compared partially with those obtained using relativistic configuration-interaction approach. Moreover, combined with experimental data, previously given in the literature, and pseudo-relativistic HartreeFock estimates, the field shifts (FSs) and specific mass shifts (SMSs) of numerous configurations are deduced: FS (5d 1 6s 2 ) ¼

The second spectrum of niobium: I. Accurate fine structure study of even-parity levels

“…One can note that magnetic A values are on the whole similar to those given by Young et al [18], when resorting to the RCI approach, but are different when having recourse to the MCDF one. We have already discussed these comparisons in our previous papers [6][7][8][9]. As regards experimental work, our computed values confirm totally the Nilson and Ivarson data [19], except those given with the biggest relative uncertainty, i.e.…”

“…Later, other palladium group ions were studied successfully with the same goal: Mo II [2], Ru II [3], Pd II [4] and Ag II [5]. Recently, we carried out fine structure (FS) studies of Zr II [6], Hf II [7], Ti II [8] and Ta II [9], enhancing previous works by giving more accurate spin-orbit and Slater integral values and very often for the first time the leading eigenvector percentages of levels and calculated Landé g-factors. Moreover, sometimes we eliminated erroneous levels reported in earlier analyses.…”

Full hyperfine structure study of singly ionized tantalum

“…Correlation is introduced through relativistic configuration interaction. The total disagreement displayed between courageous Norquist and Beck calculations and the present semiempirical results, already pointed out in the cases of Zr II [7] and Hf II [8], is due to different mixing of LS levels, by spin-orbit interactions and consequently in the expansions of the magnetic hfs factor A in intermediate coupling, to different occupations of the orbitals, to different evaluations of monoelectronic hfs constants etc. As regards experimental work, our computed values confirm on the whole the well-founded Messnars and Guthöhrlein data [22].…”

“…The opacity of unknown lines affects the observed structure of stellar spectra, so extensive improvements in the accuracy and completeness of the atomic data are welcome. Recently, we have achieved semiempirical hyperfine structure (hfs) investigations in Zr II [7], Hf II [8] and Ti II [9]. This time we propose a similar study concerning Ta II, both for even-and odd-parity levels, since hfs of Ta II levels, large enough to modify the profiles of lines that might be detected in stellar spectra, are also of interest to the astrophysical community for abundance determination and spectrum synthesis.…”

Semi-empirical studies of atomic transition probabilities, oscillator strengths and radiative lifetimes in Hf II

“…We had recourse to a semi-empirical method for parametrization of oscillator strengths. The complete details of this method were already described in previous paper [6]; nevertheless let us mention once more that we transformed angular coefficients of the transition matrix from SL coupling to intermediate one, using fine structure eigenvector amplitudes, previously determined [7][8][9] and presently reanalyzed for odd-parity ones.…”