Normal mode analysis on the relaxation of an excited nitromethane molecule in argon bath
- Texas A & M Univ., College Station, TX (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Baker Univ., Baldwin City, KS (United States)
In our previous work [Rivera-Rivera et al., J. Chem. Phys. 142, 014303 (2015)], classical molecular dynamics simulations followed the relaxation, in a 300 K Ar bath at a pressure of 10-400 atm, of nitromethane (CH3NO2) instantaneously excited by statistically distributing 50 kcal/mol among all its internal degrees of freedom. Both rotational and vibrational energies decayed with nonexponential curves. In this present work, we explore mode-specific mechanisms at work in the decay process. With the separation of rotation and vibration developed by Rhee and Kim [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. The saved CH3NO2 positions and momenta were converted into mode-specific energies whose decay was monitored over 1000 ps. Lastly, the results identify vibrational and rotational modes that promote/resist energy lost and drive nonexponential behavior.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division; US Army Research Office (ARO); USDOE
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1556908
- Alternate ID(s):
- OSTI ID: 1542693
- Journal Information:
- Journal of Chemical Physics, Vol. 151, Issue 3; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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