Resonances close to the first ionization threshold of selenium

Abstract

Relativistic multichannel theory has been used to calculate the even-parity Rydberg states and odd-parity autoionizing (AI) Rydberg spectrum converging to the limit of second and third excited core states of selenium (Se), taking into account the ionic core dipole polarization effect caused by the Rydberg electron. Six even-parity Rydberg series $4s^{2}4p^3({}^4{S}^o)n{p}^3{P}_{0,1,2}$ and $4s^{2}4p^3({}^4{S}^o)n{p}^5{P}_{1,2,3}$ are calculated, along with AI Rydberg states converging to $4s^{2}4p^3({}^2{D}_{3/2}^o)$ or $4s^{2}4p^3({}^2{D}_{5/2}^o)$ in $J^{\pi }={(1)}^{-},{(2)}^{-}$ or ${(3)}^{-}$ symmetry. In general, there is less than a 0.05 difference between calculated and experimental quantum defects. The influence of the perturbers on quantum defects and peak profiles has all been investigated. The accuracy of our calculations allows us to provide a reliable the assignment of the measured AI Rydberg states and the accompanying total angular momentum.

Keywords:

• autoionizing states
• dipole polarization
• selenium
• relativistic multichannel theory
• Rydberg series

Acknowledgments

The authors deeply appreciate Dr. R. Li for fruitful discussion and providing experimental data.

Additional information

Funding

This study was supported by: the National Key Research and Development Program of China [Grant Nos. 2017YFA0402300, 2017YFA0304900]; Strategic Priority Research Program of Chinese Academy of Sciences [Grant No. XDPB08-3]; Beijing Natural Science Foundation [Grant No. 1212014]; Fundamental Research Funds for the Central Universities, and Specialized Research fund for CAS Key Laboratory of Geospace Environment [GE2020-01].