A Born-Oppenheimer photolysis model of N2O fractionation
نویسندگان
چکیده
منابع مشابه
A Born-Oppenheimer photolysis model of N2O fractionation
[1] The isotopically light N2O produced by microbial activity is thought to be balanced by the return of heavy stratospheric nitrous oxide. The Yung and Miller [1997] method that first explained these trends yields photolytic fractionation factors half those observed by experiment or predicted quantum mechanically, however. To address these issues, we present here a Born-Oppenheimer photolysis ...
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In previous reports on isotopic fractionation in the ultraviolet photolysis of nitrous oxide (N2O) only enrichments of heavy isotopes in the remaining N2O fraction have been found. However, most direct photolysis experiments have been performed at wavelengths far from the absorption maximum at 182 nm. Here we present high-precision measurements of the 15N and 18O fractionation constants (ε) in ...
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The biogeochemical cycling of nitrous oxide plays an important role in greenhouse forcing and ozone regulation. Laboratory studies of N2O:N2 mixtures irradiated between 193-207 nm reveal a significant enrichment of the residual heavy nitrous oxide isotopomers. The isotopic signatures resulting from photolysis are well modeled by an irreversible Rayleigh distillation process, with large enrichme...
متن کاملThe Born-Oppenheimer Approximation
where R is the set of nuclear coordinates and r is the set of electronic coordinates. If spin-orbit effects are important, they can be added through a spin-orbit operator Ĥso. Unfortunately, the V̂eN(r,R) term prevents us from separating Ĥ into nuclear and electronic parts, which would allow us to write the molecular wavefunction as a product of nuclear and electronic terms, Ψ(r,R) = Ψ(r)χ(R). W...
متن کاملIsotopomer fractionation in the UV photolysis of N2O: 2. Further comparison of theory and experiment
[1] Wavelength-dependent fractionation of various isotopomers in the photodissociation of N2O is studied. The absorption cross sections are calculated by a time-independent reflection principle, related to the Prakash et al. (2005) treatment but now with an inclusion of the NN stretching coordinate and both the 2A0 and 1A00 electronic excited states. The added 1A00 state is found to have little...
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ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 2003
ISSN: 0094-8276
DOI: 10.1029/2003gl016932