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Donovan RJ, Lawley KP, Ridley T. Heavy Rydberg behaviour in high vibrational levels of some ion-pair states of the halogens and inter-halogens. J Chem Phys 2015; 142:204306. [PMID: 26026446 DOI: 10.1063/1.4921560] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the identification of heavy Rydberg resonances in the ion-pair spectra of I2, Cl2, ICl, and IBr. Extensive vibrational progressions are analysed in terms of the energy dependence of the quantum defect δ(Eb) rather than as Dunham expansions. This is shown to define the heavy Rydberg region, providing a more revealing fit to the data with fewer coefficients and leads just as easily to numbering data sets separated by gaps in the observed vibrational progressions. Interaction of heavy Rydberg states with electronic Rydberg states at avoided crossings on the inner wall of the ion-pair potential is shown to produce distinctive changes in the energy dependence of δ(Eb), with weak and strong interactions readily distinguished. Heavy Rydberg behaviour is found to extend well below near-dissociation states, down to vibrational levels ∼18,000-20,000 cm(-1) below dissociation. The rapid semi-classical calculation of δ(Eb) for heavy Rydberg states is emphasised and shows their absolute magnitude to be essentially the volume of phase space excluded from the vibrational motion by avoiding core-core penetration of the ions.
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Affiliation(s)
- Robert J Donovan
- School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, United Kingdom
| | - Kenneth P Lawley
- School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, United Kingdom
| | - Trevor Ridley
- School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, United Kingdom
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Gao S, Mo Y. Ion-pair dissociation dynamics of H2S in the photon energy range 15.26-15.55 eV. J Phys Chem A 2011; 115:1781-6. [PMID: 21344893 DOI: 10.1021/jp108808w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The H(+) velocity map images from the ion-pair dissociation of H(2)S + hν → SH(-)(X(1)Σ(+), υ = 0, 1) + H(+) have been measured at the excitation energies 15.259, 15.395, and 15.547 eV, respectively. The experimental results show that most of the available energies are transformed into the translational energies. The angular distributions of the fragments SH(-)(X(1)Σ(+), υ = 0) indicate that the dissociation occurs via pure parallel transition with limiting anisotropy parameter of +2. Because the ion-pair dissociation usually occurs via the predissociation of Rydberg states, this suggests that the ion cores of the excited Rydberg states have linear geometries. The geometries and electronic structures of the linear H(2)S(+) have been calculated employing the quantum chemistry calculation method at the CASPT2/avqz level. The electronic structures for the ion-pair states have been calculated at the CASSCF/avtz level, which indicates that the equilibrium geometries of the ion-pair states have bent geometries.
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Affiliation(s)
- Shumin Gao
- Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing 100084, China
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Liu K, Song D, Kong FA, Li J, Mo Y. Ion-Pair Dissociation Dynamics of SO 2 in the Photon Energy Range 14.87−15.15 eV. J Phys Chem A 2010; 114:9999-10004. [DOI: 10.1021/jp105206q] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kai Liu
- The State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, China, and Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing, 100084, China
| | - Di Song
- The State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, China, and Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing, 100084, China
| | - Fan-ao Kong
- The State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, China, and Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing, 100084, China
| | - Juan Li
- The State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, China, and Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing, 100084, China
| | - Yuxiang Mo
- The State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, China, and Department of Physics and Key Laboratory for Atomic and Molecular Nanosciences, Tsinghua University, Beijing, 100084, China
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