Theoretical molecular spectroscopy of actinide compounds: The ThO molecule

• Published in: arXiv.org
• Main Authors: Zaitsevskii, Andrei V, Oleynichenko, Alexander V, Eliav, Ephraim
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 26.04.2023
• Subjects: Clusters; Electron states; Excitation; Modelling; Molecular spectroscopy; Physics - Atomic Physics; Physics - Chemical Physics; Physics - Computational Physics; Thorium
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2304.13435

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.