Analytic empirical potentials for BeH+, BeD+, and BeT+ including up to 4th order QED in the long-range, and predictions for the halo nucleonic molecules 11BeH+ and 14BeH+.

Dattani, Nikesh S.

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https://hdl.handle.net/2142/79068 Copy

Description

Title

Analytic empirical potentials for BeH+, BeD+, and BeT+ including up to 4th order QED in the long-range, and predictions for the halo nucleonic molecules 11BeH+ and 14BeH+.

Author(s)

Dattani, Nikesh S.

Contributor(s)

• Le Roy, Robert J.
• Lach, Grzegorz
• Li Chun Fong, Lena C.M.

Issue Date

22-Jun-15

Keyword(s)

Mini-symposium: High-Precision Spectroscopy

Abstract

The 13.81(8)s half-life of the halo nucleonic atom $^{11}$Be is orders of magnitude longer than those for any other halo nucleonic atom known, and makes Be-based diatomics the most promising candidates for the formation of the first halo nucleonic molecules. However, the 4$e^-$ species LiH and BeH$^+$ are some of the first molecules for which the highest accuracy textit{ab initio} methods {it are not}, accessible, so empirical potential energy functions will be important for making predictions and for benchmarking how textit{ab initio} calculations break down at this transition from 3$e^-$ to 4$e^-$. BeH$^+$ is also very light, and has one of the most extensive data sets involving a tritium isotopologue, making it a very useful benchmark for studying Born-Oppenheimer breakdown. We therefore seek to determine an empirical analytic potential energy function for BeH$^+$ that has as much precision as possible. To this end, all available spectroscopic data for all stable isotopologues of BeH$^+$ are analyzed in a standard direct-potential-fit procedure that uses least-squares fits to optimize the parameters defining an analytic potential. The ``Morse/Long-range'' (MLR) model used for the potential energy function incorporates the inverse-power long-range tail required by theory, and the calculation of the leading long-range coefficients $C_4$, $C_6$, $C_7$, and $C_8$ include non-adiabatic terms, and up to 4th order QED corrections. As a by-product, we have calculated some fundamental properties of 1$e^-$ systems with unprecedented precision, such as the dipole, quadrupole, octupole, non-adiabatic, and mixed higher order polarizabilities of hydrogen, deuterium, and tritium. We provide good first estimates for the transition energies for the halo nucleonic species $^{11}$BeH$^+$ and $^{14}$BeH$^+$.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79068

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