Heavy Rydberg behaviour in high vibrational levels of some ion-pair states of the halogens and inter-halogens

Journal Article · Thu May 28 04:00:00 EDT 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4921560· OSTI ID:22415871

Ridley, Trevor ^[1]

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1. School of Chemistry, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ (United Kingdom)

We report the identification of heavy Rydberg resonances in the ion-pair spectra of I{sub 2}, Cl{sub 2}, ICl, and IBr. Extensive vibrational progressions are analysed in terms of the energy dependence of the quantum defect δ(E{sub b}) 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(E{sub b}), 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{sup −1} below dissociation. The rapid semi-classical calculation of δ(E{sub b}) 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.

• OSTI ID: 22415871
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 20 Vol. 142; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CHLORINE
DISSOCIATION
ENERGY DEPENDENCE
IODINE
IODINE BROMIDES
IODINE CHLORIDES
ION PAIRS
PHASE SPACE
POTENTIALS
RYDBERG STATES