Revised Interpretation of the Spectrum of Singly-Ionized Neodymium (Nd II)

Abstract

Because of the confusion between two low odd levels 1218 cm-1 apart, the complete system of levels of Nd II built on the core f3 had to be revised with the help of the 144Nd-150Nd isotope shift. The lowest odd level f3d2 6M13/2 is now at 8009.810 cm-1, 96 levels have been shifted and 126 new levels have been found. The new identifications rely upon parametric studies of the sub-configurations 4f35d6s + 4f3(4I)5d2 + 4f4(5I)6p (115 interpreted levels) and 4f3(4I)5d6p + 4f3(4I)6s6p (124 interpreted levels).

Studies of Landé gJ-factors of singly ionized neodymium isotopes (142, 143 and 145) at relatively small magnetic fields up to 334 G by collinear laser ion beam spectroscopy

“…The table contains the percentage of contribution from the leading configuration in the configuration interaction parametric studies from references [1,3]. However, calculated in both works Landé g J factors are favoring the data and leading configuration assignment of [3] (please compare the data given in Tab. 1 with present experimental results).…”

“…Discrepancies of some present Nd II level designations, between two available theoretical parametric studies (Refs. [1,3] the interpretation of the Nd II spectra is almost complete, there are still some inconsistencies for some levels. In the parametric studies, both authors used practically the same experimental data on Landé g J factors, known with accuracy of ±0.01 unit.…”

“…From the studies of some infrared lines, Blaise et al gave 687 and 684 levels for Nd I and Nd II [2], respectively. Few years later, Blaise and Wyart [3] have increased number of Nd II levels by 126. Additionally, the presence of 7 stable isotopes in the naturally occurring neodymium with comparable abundances (142-23%, 143-13%, 144-25%, 145-9%, 146-18%, 148-6% and 150-6%) and the related significant isotope shifts makes the interpretation of highly resolved spectra even more difficult task.…”

“…Although this approach is very versatile and gives accurate results, it has one week a e-mail: s.werbowy@ug.edu.pl point: it requires the knowledge of some spectroscopic data (usually taken from the experiment) to which the parameters could be fitted, enabling in this way the access to values of other unknown spectroscopic data. The accuracy of the experimental input data is crucial, because even small variations could lead to bad analysis of the complex atomic structure [3]. A very extensive recent theoretical interpretation of the odd parity levels in Nd II was presented by Wyart [1], who gave the designations for 596 odd levels of the mixed configurations 4f 3 5d6s, 4f 3 5d 2 , 4f 3 6s 2 , 4f 4 6p and 4f 5 with 53 cm −1 mean error.…”

Europium, Samarium, and Neodymium Isotopic Fractions in Metal‐Poor Stars

“…Unlike Sm, however, the atomic data for Nd do not include FTS measurements of individual isotope positions, so our reported absolute wavelengths of Nd components are based solely on measurements of the Nd energy levels. To avoid mixing measurements of energy levels from different studies, we adopt the energy levels from Blaise et al (1984). They estimate an uncertainty of AE0.005 cm À1 for each level.…”