Fine-structure splittings in low-lying triplet states of the carbon atom
Rzhevskii P. Tumakov D. Shomenov T. Bubin S.
January 2026American Physical Society
Physical Review Research
2026#8Issue 1
We present benchmark theoretical values of the fine-structure splittings in the ground 3Pe and low-lying excited 3Pe and 3De states of the C12, C13, and C14 isotopes of the neutral carbon atom. We handle the correlations in the dynamics of all particles (six electrons and a nucleus) in all considered states in the practically exact manner by employing very large expansions of the wave functions in terms of all-particle explicitly correlated Gaussian basis sets, whose nonlinear parameters were extensively optimized. The resulting wave functions were used to compute the fine-structure splittings for the three isotopes by including the leading-order spin-orbit and electron spin-spin corrections (∝α2), contribution from the electron anomalous magnetic moment (∝α3), and by taking into account the most significant couplings between the targeted and neighboring electronic states (∝α4). Our results show a notable improvement in accuracy compared to any previous theoretical calculations, are in good agreement with the best available experimental data, and demonstrate that the calculations of six-electron systems are now sufficiently advanced for precision measurement applications.
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Department of Physics, Nazarbayev University, Astana, 010000, Kazakhstan
University of Hamburg, Institute for Theoretical Physics, Hamburg, 22607, Germany
National Laboratory Astana, Nazarbayev University, Astana, 010000, Kazakhstan
Department of Physics
University of Hamburg
National Laboratory Astana
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026