$\textit{Ab initio}$ multiconfigurational calculations of experimentally significant energy levels and transition rates in Lr I $\left( Z=103 \right)$

Abstract

Large-scale multiconfigurational calculations are conducted on experimentally significant transitions in Lr I and its lanthanide homologue Lu I, exhibiting good agreement with recent theoretical and experimental results. A single reference calculation is performed, allowing for substitutions from the core within a sufficiently large active set to effectively capture the influence of the core on the valence shells, improving upon previous multiconfigurational calculations. An additional calculation utilising a multireference set is performed to account for static correlation effects which contribute to the wavefunction. Reported energies for the two selected transitions are 20716$\pm$550 $\text{cm}^{-1}$ and 28587$\pm$650 $\text{cm}^{-1}$ for $7\!s^2 8s~^{2} \! {S}_{1\!/\!2}$ $\rightarrow$ $7\!s^2 7\!p ~^{2} \! {P}^{o}_{1\!/\!2 }$ and $7\!s^2 7\!d ~^{2} \! {D}_{3\!/\!2 }$ $\rightarrow$ $7\!s^2 7\!p ~^{2} \! {P}^{o}_{1\!/\!2 }$, respectively.

Figures (2)

• Figure 1: The average radii in Bohr radii of the spectroscopic relativistic radial orbitals in Lr I. Only radial orbitals with total angular momentum $j=l+1/2$ are included for clarity. The subshells are coloured based upon their average distance from the nucleus.
• Figure 2: MCDHF calculations of the transition energy for the last four computational layers of Lr I (Lu I), as a function of computational layer for the transition of $7\!s^2 8s ~^{2} \! S_{1\!/\!2 }$$\rightarrow$$7\!s^2 7\!p ~^{2} \! P^{o}_{1\!/\!2}$ ($6s^2 7\!s ~^{2} \! S_{1\!/\!2 }$$\rightarrow$$6s^2 6p ~^{2} \! P^{o}_{1\!/\!2}$). The upper three subfigures (a)-(c) present the results for Lu I while the lower three subfigures (d)-(f) present the results for Lr I. The subfigures from left to right show how the calculations evolve as the computational model becomes larger and more core correlation is considered. The subfigures on the left (a), (d) show the transition energies for Model Two, when only valence effects are considered. The middle subfigures (b), (e) show the transition energies for Model Three. The subfigures to the right (c), (f) show the transition energies for Model Four. The calculations of Lr I are compared to the results of the previous theoretical calculations using FSCC Borschevsky_Transition_2007 and CI+MBPT Kahl_Initio_2021, while the calculations of Lu I are compared to experimental values from NIST Kramida_NIST_1999.