Normal mode analysis on the relaxation of an excited nitromethane molecule in argon bath

Rivera-Rivera, Luis A.

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https://hdl.handle.net/2142/97000 Copy

Description

Title

Normal mode analysis on the relaxation of an excited nitromethane molecule in argon bath

Author(s)

Rivera-Rivera, Luis A.

Contributor(s)

Wagner, Albert F.

Issue Date

2017-06-21

Keyword(s)

Dynamics and kinetics

Abstract

In our previous work [Rivera-Rivera textit{et al}. textit{J. Chem. Phys.} 142, 014303 (2015).] classical molecular dynamics simulations followed, in an Ar bath, the relaxation of nitromethane (CH$_3$NO$_2$) instantaneously excited by statistically distributing 50 kcal/mol among all its internal degrees of freedom. The 300 K Ar bath was at pressures of 10 to 400 atm. Both rotational and vibrational energies exhibited multi-exponential decay. This study explores mode-specific mechanisms at work in the decay process. With the separation of rotation and vibration developed by Rhee and Kim [textit{J. Chem. Phys.} 107, 1394 (1997).], one can show that the vibrational kinetic energy decomposes only into vibrational normal modes while the rotational and Coriolis energies decompose into both vibrational and rotational normal modes. Then the saved CH$_3$NO$_2$ positions and momenta can be converted into mode-specific energies whose decay over 1000 ps can be monitored. The results identify vibrational and rotational modes that promote/resist energy lost and drive multi-exponential behavior. In addition to mode-specificity, the results show disruption of IVR with increasing pressure._x000d_ _x000d_ _x000d_

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/97000

DOI

https://doi.org/10.15278/isms.2017.WH04

Copyright and License Information

Copyright 2017 Luis A. Rivera-Rivera

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