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arXiv · 2304.13435

Theoretical molecular spectroscopy of actinide compounds: The ThO molecule

Andrei V. Zaitsevskii·Alexander V. Oleynichenko·Ephraim Eliav
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Abstract

The tiny-core generalized (Gatchina) relativistic pseudopotential (GRPP) model provides an accurate approximation for many-electron Hamiltonians of molecules containing heavy atoms, ensuring a proper description of the effects of non-Coulombian electron-electron interactions, electronic self-energy and vacuum polarization. Combining this model with electron correlation treatment in the frames of the intermediate Hamiltonian Fock space coupled cluster theory employing incomplete main model spaces, one obtains a reliable and economical tool for excited state modeling. The performance of this method is assessed in applications to \textit{ab initio} modeling of excited electronic states of the thorium monoxide molecule with term energies below 20000 cm$^{-1}$. Radiative lifetimes of excited states are estimated using truncated expansions of effective and metric operators in powers of cluster amplitudes.

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Andrei V. Zaitsevskii, Alexander V. Oleynichenko, Ephraim Eliav. 2023-04-26. Theoretical molecular spectroscopy of actinide compounds: The ThO molecule. https://doi.org/10.1080/00268976.2023.2236246

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