Simulated Electronic Absorption Spectra of Sulfur-Containing Molecules Present in Earth’s Atmosphere

Farahani, Sara and Frandsen, Benjamin N. and Kjaergaard, Henrik G. and Lane, Joseph R. (2019) Simulated Electronic Absorption Spectra of Sulfur-Containing Molecules Present in Earth’s Atmosphere. Journal of physical chemistry A, 123 (3). 6605-6617. ISSN 1932-7455

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Official URL: https://pubs.acs.org/doi/abs/10.1021/acs.jpca.9b04...

Abstract or Summary

We have calculated, ab initio, the electronic absorption spectrum of sulfuric acid (H2SO4) under atmospherically relevant conditions using a nuclear ensemble approach. The experimental electronic spectrum of H2SO4 is unknown so we benchmark our theoretical results by also considering other related sulfur-containing molecules, namely, sulfur dioxide (SO2), sulfur trioxide (SO3), hydrogen sulfide (H2S), carbonyl sulfide (OCS), and carbon disulfide (CS2), where experimental spectra are available. In general, we find very good agreement between our calculated spectra, which are based on underlying EOM-CCSD electronic structure calculations, and the available experimental spectra. We show that the computational cost of these calculated spectra can be substantively reduced with negligible loss of accuracy by using a combination of results obtained with the aug-cc-pV(D+d)Z+3 and aug-cc-pV(T+d)Z+3 basis sets. Our calculated cross-section for H2SO4 in the UV/VUV region is larger than previous theoretical estimates and greater than the experimentally measured upper limits. We suggest that further experimental attempts to measure the electronic absorption spectrum of H2SO4 in the actinic region (4.0–7.5 eV, 313–167 nm) region are warranted.

Item Type:Journal article
Keywords that describe the item:Absorption Spectra Sulfur-Containing Molecules H2SO4 sulfuric acid ab initio photodissociation J-values simulation
Subjects:Q Science > QD Chemistry
Divisions:Schools > Centre for Science and Primary Industries
ID Code:7288
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Deposited On:05 May 2020 22:47
Last Modified:05 May 2020 22:47

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