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Skrzyński G, Musial M. Benchmark Study of the Electronic States of the LiRb Molecule: Ab Initio Calculations with the Fock Space Coupled Cluster Approach. Molecules 2023; 28:7645. [PMID: 38005367 PMCID: PMC10675596 DOI: 10.3390/molecules28227645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/27/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Accurate potential energy curves (PECs) are determined for the twenty-two electronic states of LiRb. In contrast to previous studies, the applied approach relies on the first principle calculations involving correlation among all electrons. The current methodology is founded on the multireference coupled cluster (CC) scheme constructed within the Fock space (FS) formalism, specifically for the (2,0) sector. The FS methodology is established within the framework of the intermediate Hamiltonian formalism and offers an intruder-free, efficient computational scheme. This method has a distinctive feature that, when applied to the doubly ionized system, provides the characteristics of the neutral case. This proves especially beneficial when investigating PECs in situations where a closed-shell molecule dissociates into open-shell fragments, yet its double positive ion forms closed-shell species. In every instance, we successfully computed continuous PECs spanning the entire range of interatomic distances, from the equilibrium to the dissociation limit. Moreover, the spectroscopic characteristic of various electronic states is presented, including relativistic effects. Relativistic corrections included at the third-order Douglas-Kroll level have a non-negligible effect on the accuracy of the determined spectroscopic constants.
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Affiliation(s)
- Grzegorz Skrzyński
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, 40-006 Katowice, Poland
| | - Monika Musial
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, 40-006 Katowice, Poland
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Skripnikov LV, Oleynichenko AV, Zaitsevskii A, Mosyagin NS, Athanasakis-Kaklamanakis M, Au M, Neyens G. Ab initio study of electronic states and radiative properties of the AcF molecule. J Chem Phys 2023; 159:124301. [PMID: 38127371 DOI: 10.1063/5.0159888] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/01/2023] [Indexed: 12/23/2023] Open
Abstract
Relativistic coupled-cluster calculations of the ionization potential, dissociation energy, and excited electronic states under 35 000 cm-1 are presented for the actinium monofluoride (AcF) molecule. The ionization potential is calculated to be IPe = 48 866 cm-1, and the ground state is confirmed to be a closed-shell singlet and thus strongly sensitive to the T,P-violating nuclear Schiff moment of the Ac nucleus. Radiative properties and transition dipole moments from the ground state are identified for several excited states, achieving a mean uncertainty estimate of ∼450 cm-1 for the excitation energies. For higher-lying states that are not directly accessible from the ground state, possible two-step excitation pathways are proposed. The calculated branching ratios and Franck-Condon factors are used to investigate the suitability of AcF for direct laser cooling. The lifetime of the metastable (1)3Δ1 state, which can be used in experimental searches of the electric dipole moment of the electron, is estimated to be of order 1 ms.
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Affiliation(s)
- Leonid V Skripnikov
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov of National Research Center "Kurchatov Institute" (NRC "Kurchatov Institute" - PNPI), 1 Orlova roscha, Gatchina, 188300 Leningrad region, Russia
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Alexander V Oleynichenko
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov of National Research Center "Kurchatov Institute" (NRC "Kurchatov Institute" - PNPI), 1 Orlova roscha, Gatchina, 188300 Leningrad region, Russia
| | - Andréi Zaitsevskii
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov of National Research Center "Kurchatov Institute" (NRC "Kurchatov Institute" - PNPI), 1 Orlova roscha, Gatchina, 188300 Leningrad region, Russia
- Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie gory 1/3, Moscow 119991, Russia
| | - Nikolai S Mosyagin
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov of National Research Center "Kurchatov Institute" (NRC "Kurchatov Institute" - PNPI), 1 Orlova roscha, Gatchina, 188300 Leningrad region, Russia
| | - Michail Athanasakis-Kaklamanakis
- Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
| | - Mia Au
- Systems Department, CERN, CH-1211 Geneva 23, Switzerland
| | - Gerda Neyens
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
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Isaev T, Makinskii D, Zaitsevskii A. Radium-containing molecular cations amenable for laser cooling. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Zaitsevskii A, Skripnikov LV, Mosyagin NS, Isaev T, Berger R, Breier AA, Giesen TF. Accurate ab initio calculations of RaF electronic structure appeal to more laser-spectroscopical measurements. J Chem Phys 2022; 156:044306. [PMID: 35105071 DOI: 10.1063/5.0079618] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Recently, a breakthrough has been achieved in laser-spectroscopic studies of short-lived radioactive compounds with the first measurements of the radium monofluoride molecule (RaF) UV/vis spectra. We report results from high-accuracy ab initio calculations of the RaF electronic structure for ground and low-lying excited electronic states. Two different methods agree excellently with experimental excitation energies from the electronic ground state to the 2Π1/2 and 2Π3/2 states, but lead consistently and unambiguously to deviations from experimental-based adiabatic transition energy estimates for the 2Σ1/2 excited electronic state, and show that more measurements are needed to clarify spectroscopic assignment of the 2Δ state.
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Affiliation(s)
- Andrei Zaitsevskii
- NRC "Kurchatov Institute"-PNPI, Orlova Roscha, 1, 188300 Gatchina, Russia
| | | | - Nikolai S Mosyagin
- NRC "Kurchatov Institute"-PNPI, Orlova Roscha, 1, 188300 Gatchina, Russia
| | - Timur Isaev
- NRC "Kurchatov Institute"-PNPI, Orlova Roscha, 1, 188300 Gatchina, Russia
| | - Robert Berger
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str 4, 35032 Marburg, Germany
| | - Alexander A Breier
- Laboratory for Astrophysics, Institute of Physics, University of Kassel, 34132 Kassel, Germany
| | - Thomas F Giesen
- Laboratory for Astrophysics, Institute of Physics, University of Kassel, 34132 Kassel, Germany
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5
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Cheng J, Wang J, Tan Z, Wu S. Theoretical Study of Photoassociation of Alkali-Metal Dimers. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024421150061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Finite-Field Calculations of Transition Properties by the Fock Space Relativistic Coupled Cluster Method: Transitions between Different Fock Space Sectors. Symmetry (Basel) 2020. [DOI: 10.3390/sym12111845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Reliable information on transition matrix elements of various property operators between molecular electronic states is of crucial importance for predicting spectroscopic, electric, magnetic and radiative properties of molecules. The finite-field technique is a simple and rather accurate tool for evaluating transition matrix elements of first-order properties in the frames of the Fock space relativistic coupled cluster approach. We formulate and discuss the extension of this technique to the case of transitions between the electronic states associated with different sectors of the Fock space. Pilot applications to the evaluation of transition dipole moments between the closed-shell-like states (vacuum sector) and those dominated by single excitations of the Fermi vacuum (the 1h1p sector) in heavy atoms (Xe and Hg) and simple molecules of heavy element compounds (I2 and TlF) are reported.
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Oleynichenko AV, Skripnikov LV, Zaitsevskii A, Eliav E, Shabaev VM. Diagonal and off-diagonal hyperfine structure matrix elements in KCs within the relativistic Fock space coupled cluster theory. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137825] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kozlov SV, Bormotova EA, Medvedev AA, Pazyuk EA, Stolyarov AV, Zaitsevskii A. A first principles study of the spin–orbit coupling effect in LiM (M = Na, K, Rb, Cs) molecules. Phys Chem Chem Phys 2020; 22:2295-2306. [DOI: 10.1039/c9cp06421d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Both fully relativistic and scalar-state based perturbation models provided the spin–orbit functions of the LiM (M = Na, K, Rb, Cs) molecules at almost experimental level of confidence.
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Affiliation(s)
- S. V. Kozlov
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
| | - E. A. Bormotova
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
| | - A. A. Medvedev
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
| | - E. A. Pazyuk
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
| | - A. V. Stolyarov
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
| | - A. Zaitsevskii
- Department of Chemistry
- Lomonosov Moscow State University
- 119991 Moscow
- Russia
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Center “Kurchatov Institute”
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Pazyuk EA, Pupyshev VI, Zaitsevskii AV, Stolyarov AV. Spectroscopy of Diatomic Molecules in an Adiabatic Approximation. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2019. [DOI: 10.1134/s0036024419100200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Jasik P, Kozicki J, Kilich T, Sienkiewicz JE, Henriksen NE. Electronic structure and rovibrational predissociation of the 2 1Π state in KLi. Phys Chem Chem Phys 2018; 20:18663-18670. [DOI: 10.1039/c8cp02551g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Adiabatic potential energy curves of the 31Σ+, 33Σ+, 21Π and 23Π states correlating for large internuclear distance with the K(4s) + Li(2p) atomic asymptote were calculated. Lifetimes of the quasi-bound rovibrational states of the 21Π state were determined by explicit time propagation.
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Affiliation(s)
- P. Jasik
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - J. Kozicki
- Faculty of Civil and Environmental Engineering
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - T. Kilich
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - J. E. Sienkiewicz
- Faculty of Applied Physics and Mathematics
- Gdańsk University of Technology
- 80-233 Gdańsk
- Poland
| | - N. E. Henriksen
- Department of Chemistry
- Building 207, Technical University of Denmark
- DK-2800 Kgs. Lyngby
- Denmark
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Jastrzebski W, Kowalczyk P, Szczepkowski J. Investigation of highly excited electronic 1Π states in KLi molecule. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.10.078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Alps K, Kruzins A, Tamanis M, Ferber R, Pazyuk EA, Stolyarov AV. Fourier-transform spectroscopy and deperturbation analysis of the spin-orbit coupled A(1)Σ(+) and b(3)Π states of KRb. J Chem Phys 2016; 144:144310. [PMID: 27083724 DOI: 10.1063/1.4945721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Fourier-transform A(1)Σ(+) - b(3)Π → X(1)Σ(+) laser-induced fluorescence spectra were recorded for the natural mixture of (39,41)K(85,87)Rb isotopologues produced in a heatpipe oven. Overall 4200 rovibronic term values of the spin-orbit coupled A(1)Σ(+) and b(3)Π states were determined with an uncertainty of about 0.01 cm(-1) in the energy range [10 850, 14 200] cm(-1) covering rotational quantum numbers J' ∈ [3, 280]. Direct deperturbation analysis of the A ∼ b complex performed within the framework of the A(1)Σ(+) ∼ b(3)ΠΩ=0,1,2 coupled-channel approach reproduced experimental data with a standard deviation of 0.004 cm(-1). Initial parameters of the internuclear potentials and spin-orbit coupling functions along with the relevant transition dipole moments were obtained by performing the quasi-relativistic electronic structure calculations. The mass-invariant molecular parameters obtained from the fit were used to predict energy and radiative properties of the A ∼ b complex for low J levels of (39)K(85)Rb as well as for (41)K(87)Rb isotopologues, allowing us to identify the most reasonable candidates for the stimulated Raman transitions between the initial uppermost vibrational levels of the a(3)Σ(+) and X(1)Σ(+) states, the intermediate levels of the A ∼ b complex, and the lowest absolute ground X(1)Σ(+)(v = 0, J = 0) state.
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Affiliation(s)
- K Alps
- Laser Center, University of Latvia, 19 Rainis Boulevard, Riga LV-1586, Latvia
| | - A Kruzins
- Laser Center, University of Latvia, 19 Rainis Boulevard, Riga LV-1586, Latvia
| | - M Tamanis
- Laser Center, University of Latvia, 19 Rainis Boulevard, Riga LV-1586, Latvia
| | - R Ferber
- Laser Center, University of Latvia, 19 Rainis Boulevard, Riga LV-1586, Latvia
| | - E A Pazyuk
- Department of Chemistry, Lomonosov Moscow State University, Leninskie gory 1/3, 119991 Moscow, Russia
| | - A V Stolyarov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie gory 1/3, 119991 Moscow, Russia
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