Isotope effects in N2O photolysis from first principles

Johan Albrecht Schmidt; Matthew Stanley Johnson; R. Schinke

Isotope effects in N2O photolysis from first principles

Johan Albrecht Schmidt, Matthew Stanley Johnson, R. Schinke

Kemisk Institut

31 Citationer (Scopus)

Abstract

For the first time, accurate first principles potential energy surfaces allow N₂O cross sections and isotopic fractionation spectra to be derived that are in agreement with all available experimental data, extending our knowledge to a much broader range of conditions. Absorption spectra of rare N-and O-isotopologues (¹⁵N¹⁴N¹⁶O, ¹⁴N¹⁵N¹⁶O, ¹⁵N₂ ¹⁶O, ¹⁴N₂¹⁷O and ¹⁴N ₂¹⁸O) calculated using wavepacket propagation are compared to the most abundant isotopologue (¹⁴N₂¹⁶O). The fractionation constants as a function of wavelength and temperature are in excellent agreement with experimental data. The study shows that excitations from the 3rd excited bending state, (0,3,0), and the first combination state, (1,1,0), are important for explaining the isotope effect at wavelengths longer than 210 nm. Only a small amount of the mass independent oxygen isotope anomaly observed in atmospheric N₂O samples can be explained as arising from photolysis.

Originalsprog	Engelsk
Tidsskrift	Atmospheric Chemistry and Physics
Vol/bind	11
Sider (fra-til)	8965-8975
ISSN	1680-7316
Status	Udgivet - 2011

Citationsformater

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title = "Isotope effects in N2O photolysis from first principles",

abstract = "For the first time, accurate first principles potential energy surfaces allow N2O cross sections and isotopic fractionation spectra to be derived that are in agreement with all available experimental data, extending our knowledge to a much broader range of conditions. Absorption spectra of rare N-and O-isotopologues (15N14N16O, 14N15N16O, 15N2 16O, 14N217O and 14N 218O) calculated using wavepacket propagation are compared to the most abundant isotopologue (14N216O). The fractionation constants as a function of wavelength and temperature are in excellent agreement with experimental data. The study shows that excitations from the 3rd excited bending state, (0,3,0), and the first combination state, (1,1,0), are important for explaining the isotope effect at wavelengths longer than 210 nm. Only a small amount of the mass independent oxygen isotope anomaly observed in atmospheric N2O samples can be explained as arising from photolysis.",

author = "Schmidt, {Johan Albrecht} and Johnson, {Matthew Stanley} and R. Schinke",

year = "2011",

language = "English",

volume = "11",

pages = "8965--8975",

journal = "Atmospheric Chemistry and Physics",

issn = "1680-7316",

publisher = "Copernicus GmbH",

}

TY - JOUR

T1 - Isotope effects in N2O photolysis from first principles

AU - Schmidt, Johan Albrecht

AU - Johnson, Matthew Stanley

AU - Schinke, R.

PY - 2011

Y1 - 2011

N2 - For the first time, accurate first principles potential energy surfaces allow N2O cross sections and isotopic fractionation spectra to be derived that are in agreement with all available experimental data, extending our knowledge to a much broader range of conditions. Absorption spectra of rare N-and O-isotopologues (15N14N16O, 14N15N16O, 15N2 16O, 14N217O and 14N 218O) calculated using wavepacket propagation are compared to the most abundant isotopologue (14N216O). The fractionation constants as a function of wavelength and temperature are in excellent agreement with experimental data. The study shows that excitations from the 3rd excited bending state, (0,3,0), and the first combination state, (1,1,0), are important for explaining the isotope effect at wavelengths longer than 210 nm. Only a small amount of the mass independent oxygen isotope anomaly observed in atmospheric N2O samples can be explained as arising from photolysis.

AB - For the first time, accurate first principles potential energy surfaces allow N2O cross sections and isotopic fractionation spectra to be derived that are in agreement with all available experimental data, extending our knowledge to a much broader range of conditions. Absorption spectra of rare N-and O-isotopologues (15N14N16O, 14N15N16O, 15N2 16O, 14N217O and 14N 218O) calculated using wavepacket propagation are compared to the most abundant isotopologue (14N216O). The fractionation constants as a function of wavelength and temperature are in excellent agreement with experimental data. The study shows that excitations from the 3rd excited bending state, (0,3,0), and the first combination state, (1,1,0), are important for explaining the isotope effect at wavelengths longer than 210 nm. Only a small amount of the mass independent oxygen isotope anomaly observed in atmospheric N2O samples can be explained as arising from photolysis.

M3 - Journal article

SN - 1680-7316

VL - 11

SP - 8965

EP - 8975

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

ER -

Isotope effects in N2O photolysis from first principles

Abstract

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