2023/01/13 by Fang Hao, Fang, Hao, Yong-Hui Zhang +5 · 1 citation
Engineering · Physics and Astronomy · #Advanced Chemical Physics Studies #Atomic Physics (physics.atom-ph) #Atomic and Molecular Physics #FOS: Physical sciences #Spacecraft and Cryogenic Technologies
paper · pdf · doi:10.48550/arxiv.2301.05442
openalex publication_date 2023/01/13 · openalex created_date 2023/01/17 · openalex updated_date 2026/07/28
B-spline functions have been widely used in computational atomic physics. Different from the traditional B-spline basis (a simple product of two B-splines), the recently developed correlated B-spline basis functions(C-BSBF), in which the interelectronic coordinate r12 is included explicitly, have greatly improved the computational accuracy of polarizability [S. J. Yang et al., Phys. Rev. A 95, 062505 (2017)] and bethe logarithm [ S. J. Yang et al., Phys. Rev. A 100, 042509 (2019)] for singlet states of helium. Here, we report the extension of the C-BSBF to the leading relativistic and QED correction calculations for energy levels of the 1 1S, 2 1S, 2 3S, and 3 3S states of helium. The relativistic kinetic term p14, contact potential δ3(r1), δ3(r12) and Araki-Sucher correction ⟨ 1/r123 ⟩ are calculated by using the global operator method, in which r12n and r12nln r12 involved are calculated with the generalization of Laplace's expansions. The obtained values for the ground state are δErel/α2=-1.951 754 7(2) and δEQED/α3=57.288 165(2), consistent with previous results, which opens the possibility of calculating higher-order relativistic and QED effects using the C-BSBF.