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Szczepkowski J, Gronowski M, Grochola A, Jastrzebski W, Tomza M, Kowalczyk P. Excited Electronic States of Sr 2: Ab Initio Predictions and Experimental Observation of the 2 1Σ u+ State. J Phys Chem A 2023; 127:4473-4482. [PMID: 37192534 DOI: 10.1021/acs.jpca.3c02056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Despite its apparently simple nature with four valence electrons, the strontium dimer constitutes a challenge for modern electronic structure theory. Here we focus on excited electronic states of Sr2, which we investigate theoretically up to 25000 cm-1 above the ground state, to guide and explain new spectroscopic measurements. In particular, we focus on potential energy curves for the 11Σu+, 21Σu+, 11Πu, 21Πu, and 11Δu states computed using several variants of ab initio coupled-cluster and configuration-interaction methods to benchmark them. In addition, a new experimental study of the excited 21Σu+ state using polarization labeling spectroscopy is presented, which extends knowledge of this state to high vibrational levels, where perturbation by higher electronic states is observed. The available experimental observations are compared with the theoretical predictions and help to assess the accuracy and limitations of employed theoretical models. The present results pave the way for future more accurate theoretical and experimental spectroscopic studies.
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Affiliation(s)
- Jacek Szczepkowski
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Marcin Gronowski
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warszawa, Poland
| | - Anna Grochola
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
| | | | - Michał Tomza
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warszawa, Poland
| | - Paweł Kowalczyk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warszawa, Poland
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2
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Zeid I, Atallah T, Kontar S, Chmaisani W, El-Kork N, Korek M. Theoretical electronic structure of the molecules SrX (X = Li, Na, K) toward laser cooling study. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.01.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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3
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Multi-reference perturbation theory study on the CsYb molecule including the spin-orbit coupling. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.03.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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4
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Shao Q, Deng L, Xing X, Gou D, Kuang X, Li H. Ground State Properties of the Polar Alkali-Metal–Ytterbium and Alkaline-Earth-Metal–Ytterbium Molecules: A Comparative Study. J Phys Chem A 2017; 121:2187-2193. [DOI: 10.1021/acs.jpca.6b11741] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qinqin Shao
- Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Lijuan Deng
- Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Xiaodong Xing
- Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Dezhi Gou
- Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Xiaoyu Kuang
- Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Hui Li
- Laboratoire
Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, 91405 Orsay, France
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5
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Tomza M. Cold interactions and chemical reactions of linear polyatomic anions with alkali-metal and alkaline-earth-metal atoms. Phys Chem Chem Phys 2017; 19:16512-16523. [DOI: 10.1039/c7cp02127e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cold interactions and channels of chemical reactions between linear polyatomic anions and atoms are investigated, opening the way for sympathetic cooling and controlled chemistry in these systems.
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Affiliation(s)
- Michał Tomza
- Centre of New Technologies
- University of Warsaw
- 02-097 Warsaw
- Poland
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6
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Pazyuk EA, Zaitsevskii AV, Stolyarov AV, Tamanis M, Ferber R. Laser synthesis of ultracold alkali metal dimers: optimization and control. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4534] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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Tomza M. Energetics and Control of Ultracold Isotope-Exchange Reactions between Heteronuclear Dimers in External Fields. PHYSICAL REVIEW LETTERS 2015; 115:063201. [PMID: 26296115 DOI: 10.1103/physrevlett.115.063201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Indexed: 06/04/2023]
Abstract
We show that isotope-exchange reactions between ground-state alkali-metal, alkaline-earth-metal, and lanthanide heteronuclear dimers consisting of two isotopes of the same atom are exothermic with an energy change in the range of 1-8000 MHz, thus resulting in cold or ultracold products. For these chemical reactions, there are only one rovibrational and at most several hyperfine possible product states. The number and energetics of open and closed reactive channels can be controlled by the laser and magnetic fields. We suggest a laser-induced isotope- and state-selective Stark shift control to tune the exothermic isotope-exchange reactions to become endothermic, thus providing the ground for testing models of the chemical reactivity. The present proposal opens the way for studying the state-to-state dynamics of ultracold chemical reactions beyond the universal limit with a meaningful control over the quantum states of both reactants and products.
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Affiliation(s)
- Michał Tomza
- ICFO-Institut de Ciéncies Fotóniques, Avenue Carl Friedrich Gauss, 3, 08860 Castelldefels, Spain and Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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8
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Pototschnig JV, Krois G, Lackner F, Ernst WE. Investigation of the RbCa molecule: Experiment and theory. JOURNAL OF MOLECULAR SPECTROSCOPY 2015; 310:126-134. [PMID: 25922550 PMCID: PMC4407902 DOI: 10.1016/j.jms.2015.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/12/2015] [Indexed: 06/04/2023]
Abstract
We present a thorough theoretical and experimental study of the electronic structure of RbCa. The mixed alkali-alkaline earth molecule RbCa was formed on superfluid helium nanodroplets. Excited states of the molecule in the range of 13 000-23 000 cm-1 were recorded by resonance enhanced multi-photon ionization time-of-flight spectroscopy. The experiment is accompanied by high level ab initio calculations of ground and excited state properties, utilizing a multireference configuration interaction method based on multiconfigurational self consistent field calculations. With this approach the potential energy curves and permanent electric dipole moments of 24 electronic states were calculated. In addition we computed the transition dipole moments for transitions from the ground into excited states. The combination of experiment and theory allowed the assignment of features in the recorded spectrum to the excited [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] states, where the experiment allowed to benchmark the calculation. This is the first experimental work giving insight into the previously unknown RbCa molecule, which offers great prospects in ultracold molecular physics due to its magnetic and electronic dipole moment in the [Formula: see text] ground state.
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Pototschnig JV, Krois G, Lackner F, Ernst WE. Ab initio study of the RbSr electronic structure: potential energy curves, transition dipole moments, and permanent electric dipole moments. J Chem Phys 2014; 141:234309. [PMID: 25527937 DOI: 10.1063/1.4903791] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Excited states and the ground state of the diatomic molecule RbSr were calculated by post Hartree-Fock molecular orbital theory up to 22 000 cm(-1). We applied a multireference configuration interaction calculation based on multiconfigurational self-consistent field wave functions. Both methods made use of effective core potentials and core polarization potentials. Potential energy curves, transition dipole moments, and permanent electric dipole moments were determined for RbSr and could be compared with other recent calculations. We found a good agreement with experimental spectra, which have been obtained recently by helium nanodroplet isolation spectroscopy. For the lowest two asymptotes (Rb (5s (2)S) + Sr (5s4d (3)P°) and Rb (5p (2)P°) + Sr (5s(2) (1)S)), which exhibit a significant spin-orbit coupling, we included relativistic effects by two approaches, one applying the Breit-Pauli Hamiltonian to the multireference configuration interaction wave functions, the other combining a spin-orbit Hamiltonian and multireference configuration interaction potential energy curves. Using the results for the relativistic potential energy curves that correspond to the Rb (5s (2)S) + Sr (5s4d (3)P°) asymptote, we have simulated dispersed fluorescence spectra as they were recently measured in our lab. The comparison with experimental data allows to benchmark both methods and demonstrate that spin-orbit coupling has to be included for the lowest states of RbSr.
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Affiliation(s)
- Johann V Pototschnig
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria
| | - Günter Krois
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria
| | - Florian Lackner
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria
| | - Wolfgang E Ernst
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria
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10
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Gopakumar G, Abe M, Hada M, Kajita M. Dipole polarizability of alkali-metal (Na, K, Rb)-alkaline-earth-metal (Ca, Sr) polar molecules: prospects for alignment. J Chem Phys 2014; 140:224303. [PMID: 24929384 DOI: 10.1063/1.4881396] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronic open-shell ground-state properties of selected alkali-metal-alkaline-earth-metal polar molecules are investigated. We determine potential energy curves of the (2)Σ(+) ground state at the coupled-cluster singles and doubles with partial triples (CCSD(T)) level of electron correlation. Calculated spectroscopic constants for the isotopes ((23)Na, (39)K, (85)Rb)-((40)Ca, (88)Sr) are compared with available theoretical and experimental results. The variation of the permanent dipole moment (PDM), average dipole polarizability, and polarizability anisotropy with internuclear distance is determined using finite-field perturbation theory at the CCSD(T) level. Owing to moderate PDM (KCa: 1.67 D, RbCa: 1.75 D, KSr: 1.27 D, RbSr: 1.41 D) and large polarizability anisotropy (KCa: 566 a.u., RbCa: 604 a.u., KSr: 574 a.u., RbSr: 615 a.u.), KCa, RbCa, KSr, and RbSr are potential candidates for alignment and orientation in combined intense laser and external static electric fields.
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Affiliation(s)
- Geetha Gopakumar
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Minori Abe
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Masahiko Hada
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Masatoshi Kajita
- National Institute of Information and Communications Technology, Koganei, Tokyo 184-8795, Japan
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11
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Tomza M, Skomorowski W, Musiał M, González-Férez R, Koch CP, Moszynski R. Interatomic potentials, electric properties and spectroscopy of the ground and excited states of the Rb2 molecule: ab initio calculations and effect of a non-resonant field*. Mol Phys 2013. [DOI: 10.1080/00268976.2013.793835] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Michał Tomza
- a Faculty of Chemistry , University of Warsaw , Warsaw , Poland
- b Theoretische Physik , Universität Kassel , Kassel , Germany
| | | | - Monika Musiał
- c Institute of Chemistry , University of Silesia , Katowice , Poland
| | - Rosario González-Férez
- d Instituto Carlos I de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear , Universidad de Granada , Granada , Spain
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12
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Gopakumar G, Abe M, Hada M, Kajita M. Ab initiostudy of ground and excited states of6Li40Ca and6Li88Sr molecules. J Chem Phys 2013; 138:194307. [DOI: 10.1063/1.4804622] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Stellmer S, Pasquiou B, Grimm R, Schreck F. Creation of ultracold Sr(2) molecules in the electronic ground state. PHYSICAL REVIEW LETTERS 2012; 109:115302. [PMID: 23005642 DOI: 10.1103/physrevlett.109.115302] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Indexed: 06/01/2023]
Abstract
We report on the creation of ultracold (84)Sr(2) molecules in the electronic ground state. The molecules are formed from atom pairs on sites of an optical lattice using stimulated Raman adiabatic passage (STIRAP). We achieve a transfer efficiency of 30% and obtain 4×10(4) molecules with full control over the external and internal quantum state. STIRAP is performed near the narrow (1)S(0)-(3)P(1) intercombination transition, using a vibrational level of the 1(0(u)(+)) potential as an intermediate state. In preparation of our molecule association scheme, we have determined the binding energies of the last vibrational levels of the 1(0(u)(+)), 1(1(u)) excited-state and the X (1)Σ(g)(+) ground-state potentials. Our work overcomes the previous limitation of STIRAP schemes to systems with magnetic Feshbach resonances, thereby establishing a route that is applicable to many systems beyond alkali-metal dimers.
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Affiliation(s)
- Simon Stellmer
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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Reinaudi G, Osborn CB, McDonald M, Kotochigova S, Zelevinsky T. Optical production of stable ultracold (88)Sr(2) molecules. PHYSICAL REVIEW LETTERS 2012; 109:115303. [PMID: 23005643 DOI: 10.1103/physrevlett.109.115303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 08/21/2012] [Indexed: 06/01/2023]
Abstract
We have produced large samples of stable ultracold (88)Sr(2) molecules in the electronic ground state in an optical lattice. The fast, all-optical method of molecule creation involves a near-intercombination-line photoassociation pulse followed by spontaneous emission with a near-unity Franck-Condon factor. The detection uses excitation to a weakly bound electronically excited vibrational level corresponding to a very large dimer and yields a high-Q molecular vibronic resonance. This is the first of two steps needed to create deeply bound (88)Sr(2) for frequency metrology and ultracold chemistry.
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Affiliation(s)
- G Reinaudi
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
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15
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Ulmanis J, Deiglmayr J, Repp M, Wester R, Weidemüller M. Ultracold Molecules Formed by Photoassociation: Heteronuclear Dimers, Inelastic Collisions, and Interactions with Ultrashort Laser Pulses. Chem Rev 2012; 112:4890-927. [PMID: 22931226 DOI: 10.1021/cr300215h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juris Ulmanis
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Johannes Deiglmayr
- Laboratorium für Physikalische
Chemie, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Marc Repp
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Roland Wester
- Institut für Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25/3, 6020 Innsbruck, Austria
| | - Matthias Weidemüller
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
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Skomorowski W, Pawłowski F, Koch CP, Moszynski R. Rovibrational dynamics of the strontium molecule in the AΣu+1, c3Πu, and aΣu+3 manifold from state-of-the-art ab initio calculations. J Chem Phys 2012; 136:194306. [DOI: 10.1063/1.4713939] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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17
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Affiliation(s)
- Christiane P. Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Strasse 40,
34132 Kassel, Germany
| | - Moshe Shapiro
- Department
of Chemistry, University of British Columbia, Vancouver, Canada V6T
1Z1, and Department of Chemical Physics, The Weizmann Institute, Rehovot, Israel 76100
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