Radiative Transition Parameters in Atomic Lanthanum from Pseudo-Relativistic Hartree–Fock and Fully Relativistic Dirac–Hartree–Fock Calculations

Sébastien Gamrath,Patrick Palmeri,Pascal Quinet

doi:10.3390/atoms7010038

Abstract

Calculated radiative transition probabilities and oscillator strengths are reported for 392 lines of neutral lanthanum (La I) atom in the spectral range from the near ultraviolet to the mid infrared. They were obtained using two different theoretical methods based on the pseudo-relativistic Hartree–Fock (HFR) and the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) approaches, both including the most important intravalence and core-valence electron correlations. The quality of these radiative parameters was assessed through detailed comparisons between the results obtained using different physical models and between our theoretical results and the experimental data, where available. Of the total number of La I lines listed in the present work, about 60% have gf- and gA-values determined for the first time.

Highlights

The determination of radiative parameters in lanthanide atoms and ions has been the subject of many experimental and theoretical studies over the past few decades
La I (Z = 57), is characterized by the 5d6s2 2 D3/2 ground level, while, the lowest excited levels belong to many different configurations such as 5d6s2, 5d2 6s, 5d3, 4f6s6p, 5d2 7s, 5d6s7s, for the even parity, and 5d6s6p, 5d2 6p, 4f5d6s, 6s2 6p, 4f6s2, for the odd parity, according to the National Institute of Standards and Technology (NIST) database [6]
We report on moderately large-scale calculations of radiative decay rates in neutral lanthanum atom using two different methods, i.e., the pseudo-relativistic Hartree–Fock (HFR) and the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) approaches

Summary

Introduction

The determination of radiative parameters in lanthanide atoms and ions has been the subject of many experimental and theoretical studies over the past few decades. La I (Z = 57), is characterized by the 5d6s2 2 D3/2 ground level, while, the lowest excited levels belong to many different configurations such as 5d6s2 , 5d2 6s, 5d3 , 4f6s6p, 5d2 7s, 5d6s7s, for the even parity, and 5d6s6p, 5d2 6p, 4f5d6s, 6s2 6p, 4f6s2 , for the odd parity, according to the National Institute of Standards and Technology (NIST) database [6]. The overlap of these configurations is responsible for the strong mixing of most energy levels, which makes both experimental and theoretical analyses very difficult. The first measurements of transition probabilities in La I were published by Corliss and Bozman [7]

Methods

Results

Conclusion