Extended measurements and an experimental accuracy effective Hamiltonian model for the 3ν2 and ν2+ν4 states of ammonia

Yu, Shanshan

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https://hdl.handle.net/2142/100483 Copy

Description

Title

Extended measurements and an experimental accuracy effective Hamiltonian model for the 3ν2 and ν2+ν4 states of ammonia

Author(s)

Yu, Shanshan

Contributor(s)

• Pirali, Olivier
• Drouin, Brian
• Sung, Keeyoon
• Pearson, John
• Pearson, Jeniveve

Issue Date

2018-06-21

Keyword(s)

Mini-symposium: Far-Infrared Spectroscopy

Date of Ingest

• 2018-08-17T16:08:57Z
• 2018-12-12T22:37:42Z

Abstract

The infrared spectrum of ammonia has proven to be highly problematic for effective Hamiltonian analysis. As a result, previous studies failed to model the 3ν2 and ν2 + ν4 bands of the spectrum close to experimental accuracy. To remedy this a global fit of the 3ν2 and ν2 + ν4 bands has been undertaken using SPFIT. The analysis includes about 1000 newly assigned vibrational transitions in 3ν2 to 2ν2 as well as inversion transitions in 3ν2 to 3ν2. The spectra were a long path infrared absorption spectrum recorded with the Synchrotron light source at SOLEIL, with a path length of 180 m and a resolution of 0.0011 cm−1 at room temperature and 1 Torr of pressure, and a mid-infrared discharge spectrum recorded similarly at SOLEIL, with a path length of 0.7 m and resolution .004 cm−1 at 10 Torr and 900 K. Our fit has achieved experimental accuracy through the use of a number of terms that had not previously been in the Hamiltonian proving that ammonia is tractable to effective Hamiltonians despite previous beliefs.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Genre of Resource

Conference Paper / Presentation

Language

eng

Permalink

http://hdl.handle.net/2142/100483

DOI

10.15278/isms.2018.RI08

Copyright and License Information

Copyright 2018 Shanshan Yu

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