Journal article
Accurate Global Potential Energy Surface and Reaction Dynamics for the Ground State of HgBr2
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, Vol.109(39), pp.8765-8773
10/06/2005
Handle:
https://hdl.handle.net/2376/107783
PMID: 16834279
Abstract
A global potential energy surface (PES) for the 1A‘ ground state of HgBr2 has been constructed in order to determine the rate constants for atmospherically important reactions involving mercury and bromine. The total energy of HgBr2 was calculated by the multireference configuration interaction level of theory with series of correlation consistent basis sets up to quadruple-ζ quality with subsequent extrapolation to the complete basis set limit. An additive correction for spin−orbit coupling was also included. The global PES was represented piecewise by interpolating three separate parts of the surface with the reproducing kernel Hilbert space method and connecting them smoothly by switch functions. Quasiclassical trajectory calculations carried out on the surface yielded 298 K thermal rate constants of 3.89 × 10-11 cm3/(mol·s) for the abstraction reaction HgBr + Br → Hg + Br2, 2.98 × 10-11 cm3/(mol·s) for the recombination reaction Br + HgBr → HgBr2, and 3.97 × 10-11 cm3/(mol·s) for the exchange reaction Br + HgBr → BrHg + Br. The insertion reaction Hg + Br2 → HgBr2 was found to have a high barrier of 27.2 kcal/mol and a very small rate constant of just 2.74 × 10-31 cm3/(mol·s) determined by the microcanonical variational transition state theory method. The implications of the obtained results to the description of the mechanism of recently observed polar tropospheric mercury depletion events are briefly discussed.
Metrics
5 Record Views
Details
- Title
- Accurate Global Potential Energy Surface and Reaction Dynamics for the Ground State of HgBr2
- Creators
- Nikolai B BalabanovBenjamin C SheplerKirk A Peterson
- Publication Details
- The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, Vol.109(39), pp.8765-8773
- Academic Unit
- Chemistry, Department of
- Publisher
- American Chemical Society
- Identifiers
- 99900547372901842
- Language
- English
- Resource Type
- Journal article