Roaming and spectroscopy

Bowman, Joel

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https://hdl.handle.net/2142/55844 Copy

Description

Title

Roaming and spectroscopy

Author(s)

Bowman, Joel

Issue Date

2014-06-16

Keyword(s)

Mini-symposium: Spectroscopy in Kinetics and Dynamics

Abstract

Accurate ab initio theoretical/computational work on dynamics and spectroscopy begins with a potential energy surface (PES). My talk therefore begins with a brief review of progress we have made in developing accurate ab initio global PESs for reaction dynamics. “Roaming” is an unusual alternate pathway to reaction products that was found in the unimolecular dissociation of H$_2$CO by running roughly 100 000 trajectories on such a PES. The signatures of roaming were seen in the spectroscopic detection of the rotational states of CO correlated with translational energy distribution of the H$_2$. I will discuss roaming in NO$_3$ photodissociation to NO+O$_2$ and give a short history of the topic. In particular I will recount how poor Franck-Condon factors in pioneering LIF detection experiments in 1997 of the low-lying vibrational states of O$_2$ plus the assumption of a “prior” vibrational distribution led to the wrong conclusions about the O$_2$ vibrational-state distribution. Later more sophisticated experiments obtained the correct vibrational distribution, which led to the (correct) speculation about roaming in this system. I conclude with some comments about roaming wavefunctions and will wonder aloud about ways to detect wavefunctions spectroscopically. (Roaming wavefunctions have been reported by Hua Guo and co-workers for the MgH$_2$.)

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/55844

DOI

https://doi.org/10.15278/isms.2014.MH01

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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