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Donovan RJ, Kirrander A, Lawley KP. Heavy Rydberg and ion-pair states: chemistry, spectroscopy and theory. INT REV PHYS CHEM 2022. [DOI: 10.1080/0144235x.2022.2077024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Robert J. Donovan
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Kenneth P. Lawley
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
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2
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Giannakeas P, Eiles MT, Robicheaux F, Rost JM. Dressed Ion-Pair States of an Ultralong-Range Rydberg Molecule. PHYSICAL REVIEW LETTERS 2020; 125:123401. [PMID: 33016746 DOI: 10.1103/physrevlett.125.123401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
We predict the existence of a universal class of ultralong-range Rydberg molecular states whose vibrational spectra form trimmed Rydberg series. A dressed ion-pair model captures the physical origin of these exotic molecules, accurately predicts their properties, and reveals features of ultralong-range Rydberg molecules and heavy Rydberg states with a surprisingly small Rydberg constant. The latter is determined by the small effective charge of the dressed anion, which outweighs the contribution of the molecule's large reduced mass. This renders these molecules the only known few-body systems to have a Rydberg constant smaller than R_{∞}/2.
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Affiliation(s)
- P Giannakeas
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Street 38, D-01187 Dresden, Germany
| | - Matthew T Eiles
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Street 38, D-01187 Dresden, Germany
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, USA
| | - Jan M Rost
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Street 38, D-01187 Dresden, Germany
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3
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Kirrander A, Jungen C, Donovan RJ, Lawley KP. Heavy Rydberg states: large amplitude vibrations. Faraday Discuss 2018; 212:175-190. [PMID: 30318538 DOI: 10.1039/c8fd00096d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Extremely large vibrational amplitude (≈8700 a.u.) heavy Rydberg levels in the HH[combining macron]1Σ+g state, located only 25 cm-1 below the ion-pair dissociation limit, are reported. The calculations are done using a hybrid log derivative/multichannel quantum defect approach that accounts for predissociation and is capable of dealing with any number of long-range closed channels, and of providing positions and widths for the heavy Rydberg resonances. In this case, resonance positions can be reproduced qualitatively using a simple diabatic model (however, the resonance widths cannot). Absolute quantum defects are derived for the vibrational series ranging from ν = 0 to ν = 2010. The influence of the Coulomb potential and continuity of heavy Rydberg behavior throughout the 1Σ+g manifold of states is demonstrated.
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Affiliation(s)
- Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, UK.
| | - Christian Jungen
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Robert J Donovan
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, UK.
| | - Kenneth P Lawley
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, UK.
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4
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Buathong S, Dunning FB. Dissociative electron attachment studies with hyperthermal Rydberg atoms. J Chem Phys 2018; 149:104303. [DOI: 10.1063/1.5049597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- S. Buathong
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
| | - F. B. Dunning
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
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5
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Dunning FB, Buathong S. Collisions of Rydberg atoms with neutral targets. INT REV PHYS CHEM 2018. [DOI: 10.1080/0144235x.2018.1512201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- F. B. Dunning
- Department of Physics and Astronomy, Rice University, Houston, TX, USA
| | - S. Buathong
- Department of Physics and Astronomy, Rice University, Houston, TX, USA
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6
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Beyer M, Merkt F. Communication: Heavy-Rydberg states of HD and the electron affinity of the deuterium atom. J Chem Phys 2018; 149:031102. [PMID: 30037250 DOI: 10.1063/1.5043186] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The electron affinity of the deuterium atom has been determined to be 6086.81(27) cm-1 from a measurement of the difference between the D+ + H- and H+ + D- ion-pair dissociation energies and a thermochemical cycle involving the electron affinity of H and the ionization energies of H and D. Heavy-Rydberg states and the ion-pair dissociation thresholds of HD were accessed with good efficiency using a three-photon excitation sequence through the B Σu+1 (v = 22, N = 1) and H¯ Σg+1 (v = 9, N = 0) intermediate levels and the threshold positions were determined using the method of threshold-ion-pair-production spectroscopy.
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Affiliation(s)
- Maximilian Beyer
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - Frédéric Merkt
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
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Kelley M, Buathong S, Dunning FB. Very strong Rydberg atom scattering in K(12p)–CH3NO2collisions: Role of transient ion pair formation. J Chem Phys 2017. [DOI: 10.1063/1.4982935] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Kelley
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
| | - S. Buathong
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
| | - F. B. Dunning
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
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Buathong S, Kelley M, Dunning FB. Probing dissociative electron attachment through heavy-Rydberg ion-pair production in Rydberg atom collisions. J Chem Phys 2016; 145:134309. [DOI: 10.1063/1.4964326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- S. Buathong
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
| | - M. Kelley
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
| | - F. B. Dunning
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA
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Buathong S, Kelley M, Wang C, Dunning F. Probing dissociative electron attachment through formation of heavy-Rydberg ion pair states in Rydberg atom collisions. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2014.10.074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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11
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Wang CH, Kelley M, Buathong S, Dunning FB. Dynamics of heavy-Rydberg ion-pair formation in K(14p,20p)-SF6, CCl4 collisions. J Chem Phys 2014; 140:234306. [PMID: 24952540 DOI: 10.1063/1.4882659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of formation of heavy-Rydberg ion-pair states through electron transfer in K(np)-SF6, CCl4 collisions is examined by measuring the velocity, angular, and binding energy distributions of the product ion pairs. The results are analyzed with the aid of a Monte Carlo collision code that models both the initial electron capture and the subsequent evolution of the ion pairs. The model simulations are in good agreement with the experimental data and highlight the factors such as Rydberg atom size, the kinetic energy of relative motion of the Rydberg atom and target particle, and (in the case of attaching targets that dissociate) the energetics of dissociation that can be used to control the properties of the product ion-pair states.
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Affiliation(s)
- C H Wang
- Department of Physics & Astronomy, Rice University, MS-61, Houston, Texas 77005, USA
| | - M Kelley
- Department of Physics & Astronomy, Rice University, MS-61, Houston, Texas 77005, USA
| | - S Buathong
- Department of Physics & Astronomy, Rice University, MS-61, Houston, Texas 77005, USA
| | - F B Dunning
- Department of Physics & Astronomy, Rice University, MS-61, Houston, Texas 77005, USA
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Lackner F, Krois G, Koch M, Ernst WE. Rubidium on Helium Droplets: Analysis of an Exotic Rydberg Complex for n* < 20 and 0 ≤ l ≤ 3. J Phys Chem Lett 2012; 3:1404-1408. [PMID: 26286790 DOI: 10.1021/jz300381y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Rubidium atom Rydberg states perturbed by helium droplets of different sizes provide insight into the role of a nanosized dielectric on the Coulomb potential. The observation of droplet size-dependent shifts of excited states with respect to bare atom states is explained by a decreased quantum defect and a lowered ionization threshold. Within the scope of a Rydberg model, we demonstrate that quantum defects and ionization potentials are constant for each specific Rydberg series, which confirms the Rydberg character of excited Rubidium states on helium droplets. A set of six Rydberg series could be identified. Individual Rydberg states are observed with effective principal quantum numbers up to n* ≈ 19 and l ≤ 3, for which the expectation value of the electron orbital radius is about 10 times larger than the droplet radius.
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Affiliation(s)
- Florian Lackner
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU
| | - Günter Krois
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU
| | - Markus Koch
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU
| | - Wolfgang E Ernst
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU
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Glass-Maujean M, Jungen C, Schmoranzer H, Haar I, Knie A, Reiss P, Ehresmann A. The transition probabilities from the ground state to the excited J = 0 1Σu(+) levels of H2: measurements and ab initio quantum defect study. J Chem Phys 2011; 135:144302. [PMID: 22010713 DOI: 10.1063/1.3646734] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The energies, widths and absolute intensities of the P(1) v'' = 0, J'' = 1 absorption transitions of H(2) have been measured in the spectral range of 81-75 nm using monochromatized synchrotron radiation. This work completes and extends previous observations, in particular those of Herzberg and Jungen [J. Mol. Spectrosc. 41, 425 (1972)]. Ab initio multichannel quantum defect theory (MQDT) is used to corroborate the spectral analysis of the experimental data. Line intensities and decay widths are also calculated using MQDT.
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Affiliation(s)
- M Glass-Maujean
- Laboratoire de Physique Moléculaire pour l'Atmosphère et l'Astrophysique, Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 05, France
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Wang J, Kim KS, Baerends EJ. Electron pair density in the lowest 1Σ(u)(+) and 1Σ(g)(+) states of H2. J Chem Phys 2011; 135:074111. [PMID: 21861560 DOI: 10.1063/1.3624571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We demonstrate and advocate the use of observable quantities derived from the two-electron reduced density matrix - pair densities, conditional densities, and exchange-correlation holes--as signatures of the type of electron correlation in a chemical bond. The prototype cases of the lowest (1)Σ(u)(+) and (1)Σ(g)(+) states of H(2), which exhibit large variation in types of bonding, ranging from strongly ionic to covalent, are discussed. Both the excited (1)Σ(g)(+) and (1)Σ(u)(+) states have been interpreted as essentially consisting of (natural) orbital configurations with an inner electron in a contracted 1sσ(g) orbital and an outer electron in a diffuse (united atom type, Rydberg) orbital. We show that nevertheless totally different correlation behavior is encountered in various states when comparing them at a common internuclear distance. Also when following one state along the internuclear distance coordinate, strong variation in correlation behavior is observed, as expected. Switches between ionic to covalent character of a state occur till very large distances (40 bohrs for states approaching the 1s3[script-l] asymptotic limit, and 282 bohrs for states approaching the 1s4[script-l] limit).
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Affiliation(s)
- Jian Wang
- School of Science, Huzhou University, Zhejiang 10083, China.
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Krishnakumar E, Denifl S, Cadež I, Markelj S, Mason NJ. Dissociative electron attachment cross sections for H2 and D2. PHYSICAL REVIEW LETTERS 2011; 106:243201. [PMID: 21770568 DOI: 10.1103/physrevlett.106.243201] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Indexed: 05/27/2023]
Abstract
New measurements of the absolute cross sections for dissociative electron attachment (DEA) in molecular hydrogen and deuterium are presented which resolve previous ambiguities and provide a test bed for theory. The experimental methodology is based upon a momentum imaging time-of-flight spectrometer that allowed us to eliminate any contributions due to electronically excited metastable neutrals and ultraviolet light while ensuring detection of all the ions. The isotope effect in the DEA process in the two molecules is found to be considerably larger than previously observed. More importantly, it is found to manifest in the polar dissociation process (also known as ion pair production) as well.
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Reinhold CO, Yoshida S, Dunning FB. Electric-field-induced dissociation of heavy Rydberg ion-pair states. J Chem Phys 2011; 134:174305. [DOI: 10.1063/1.3581832] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Vieitez MO, Ivanov TI, Reinhold E, de Lange CA, Ubachs W. Spectroscopic observation and characterization of H(+)H(-) heavy Rydberg states. J Phys Chem A 2009; 113:13237-45. [PMID: 19921940 DOI: 10.1021/jp9039918] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A series of discrete resonances was observed in the spectrum of H2, which can be unambiguously assigned to bound quantum states in the 1/R Coulombic potential of the H+H- ion-pair system. Two-step laser excitation was performed, using tunable extreme ultraviolet radiation at lambda = 94-96 nm in the first step, and tunable ultraviolet radiation in the range lambda = 310-350 nm in the second step. The resonances, detected via H+ and H2+ ions produced in the decay process, follow a sequence of principal quantum numbers (n = 140-230) associated with a Rydberg formula in which the Rydberg constant is mass scaled. The series converges upon the ionic H+H- dissociation threshold. This limit can be calculated without further assumptions from known ionization and dissociation energies in the hydrogen system and the electronegativity of the hydrogen atom. A possible excitation mechanism is discussed in terms of a complex resonance. Detailed measurements are performed to unravel and quantify the decay of the heavy Rydberg states into molecular H2+ ions, as well as into atomic fragments, both H(n = 2) and H(n = 3). Lifetimes are found to scale as n3.
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Affiliation(s)
- M O Vieitez
- Laser Centre, Vrije Universiteit, Amsterdam, Netherlands
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Corongiu G, Clementi E. Energy and Density Analyses of the 1Σu+ States in the H2 Molecule from the United Atom to Dissociation. J Phys Chem A 2009; 113:14791-9. [DOI: 10.1021/jp9049395] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giorgina Corongiu
- Dipartimento di Scienze Chimiche e Ambientali, Università dell’Insubria, Via Valleggio 11, I-22100 Como, Italy
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Corongiu G, Clementi E. Energy and density analyses of the H2 molecule from the united atom to dissociation: The ∑1g+ states. J Chem Phys 2009; 131:034301. [DOI: 10.1063/1.3168506] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Cannon M, Wang CH, Liu Y, Dunning FB, Steill JD. Temperature dependence of reactions involving electron transfer in K(np)/C2Cl4 collisions. J Chem Phys 2009; 130:244311. [PMID: 19566157 DOI: 10.1063/1.3158604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Electron transfer in K(np)-C(2)Cl(4) collisions, which leads to formation of both Cl(-) and C(2)Cl(4)(-) anions, is investigated as a function of target temperature over the range of 300-650 K. Measurements at high n (n approximately 30) show that the likelihood of Cl(-) production increases rapidly with temperature indicating the presence of a dissociation barrier. The data yield an activation energy of approximately 0.1 eV. A broad distribution of product C(2)Cl(4)(-) lifetimes is observed that extends from microseconds to milliseconds, this distribution moving toward shorter lifetimes as the target temperature is increased. The measured lifetimes are consistent with the predictions of quasiequilibrium theory. Studies at low n (n approximately 14) show a substantial fraction of the product K(+)-Cl(-) and K(+)-C(2)Cl(4)(-) ion pairs is electrostatically bound leading to creation of heavy-Rydberg ion-pair states. Variations in target temperature lead to changes in kinetic energy of relative motion of the reactants that can result in marked changes in the fraction of ion pairs that is bound, especially at low Rydberg atom velocities. In the case of bound K(+)-C(2)Cl(4)(-) ion pairs a few percent subsequently dissociate by the conversion of internal energy in the anion into translational energy of the ion pair. Analysis of the data points to a mean energy conversion of approximately 60-90 meV, much less than the available excess energy of reaction, approximately 0.7 eV.
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Affiliation(s)
- M Cannon
- Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, Texas 77005, USA.
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