From lines to states without a model

Brackertz, Stefan

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https://hdl.handle.net/2142/100642 Copy

Description

Title

From lines to states without a model

Author(s)

Brackertz, Stefan

Contributor(s)

• Asvany, Oskar
• Schlemmer, Stephan

Issue Date

2018-06-19

Keyword(s)

Mini-symposium: New Ways of Understanding Molecular Spectra

Abstract

The fundamental Ritz combination principle a originally found for atoms has also been applied to molecules as a method to reconstruct the energy states from measured lines without relying on any model Hamiltonian. In 2006 Nesbitt and coworkers b proposed to apply it to protonated methane, CH+ 5 . We used this idea to reconstruct a part of its ground state energies employing spectra of combination differences (CDs) determined from very high resolution ro-vibrational data c . Since then the method has been significantly improved d as the CD lines essentially represent kernel density estimations, a well-known tool in mathematics. Furthermore, a combinatorial approach has been developed to reconstruct vibrational ground states as well as vibrationally excited states from the CD spectra without relying on measurements at different temperatures. As a result, 1063 of the 2897 measured lines of CH+ 5 being part of four different symmetry species could be assigned. This allowed for a comparison of the measurements with the analytical model of Schmiedt et al. e as well as with the ab initio calculations of Wang and Carrington f .

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100642

DOI

10.15278/isms.2018.TH06

Copyright and License Information

Copyright 2018 Stefan Brackertz

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