Branching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics study

http://dx.doi.org/10.1021/jp0043064
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Publication Type abstract
School or College College of Science
Department Chemistry
Creator Truong, Thanh
Other Author Zhang, Shaowen
Title Branching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics study
Date 2001
Description The dynamics of the initial thermal decomposition step of gas-phase ?-HMX is investigated using the master equation method. Both the NO2 fission and HONO elimination channels were considered. The structures, energies, and Hessian information along the minimum energy paths (MEP) of these two channels were calculated at the B3LYP/cc-pVDZ level of theory. Thermal rate constants at the high-pressure limit were calculated using the canonical variational transition state theory (CVT), microcanonical variational transition state theory (?VT). The pressure-dependent multichannel rate constants and the branching ratio were calculated using the master equation method. Quantum tunneling effects in the HONO elimination are included in the dynamical calculations and found to be important at low temperatures. At the high-pressure limit, the NO2 fission channel is found to be dominant in the temperature range (500?1500 K). Both channels exhibit strong pressure dependence at high temperatures. Both reach the high-pressure limits at low temperatures. We found that the HONO elimination channel can compete with the NO2 fission, one in the low-pressure and/or high-temperature regime.
Type Text
Publisher American Chemical Society
Volume 105
Issue 11
First Page 2427
Last Page 2434
Subject Thermal decomposition; HMX
Subject LCSH Decomposition (Chemistry)
Language eng
Bibliographic Citation Zhang, H. R., & Truong, T. N. (2001). Branching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics study. Journal of Physical Chemistry A, 105(11), 2427-34.
Rights Management (c)American Chemical Society http://dx.doi.org/10.1021/jp0043064
Format Medium application/pdf
Identifier ir-main,7051
ARK ark:/87278/s6nc6jwr
Setname ir_uspace
Date Created 2012-07-30
Date Modified 2012-08-30
ID 707680
Reference URL https://collections.lib.utah.edu/ark:/87278/s6nc6jwr
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