TY - JOUR
T1 - Atmospheric Kinetics
T2 - Bimolecular Reactions of Carbonyl Oxide by a Triple-Level Strategy
AU - Long, Bo
AU - Wang, Ying
AU - Xia, Yu
AU - He, Xiao
AU - Bao, Junwei Lucas
AU - Truhlar, Donald G.
N1 - Publisher Copyright:
©
PY - 2021/6/9
Y1 - 2021/6/9
N2 - Criegee intermediates in the atmosphere serve as oxidizing agents to initiate aerosol formation, which are particularly important for atmospheric modeling, and understanding their kinetics is one of the current outstanding challenges in climate change modeling. Because experimental kinetics are still limited, we must rely on theory for the complete picture, but obtaining absolute rates from theory is a formidable task. Here, we report the bimolecular reaction kinetics of carbonyl oxide with ammonia, hydrogen sulfide, formaldehyde, and water dimer by designing a triple-level strategy that combines (i) benchmark results close to the complete-basis limit of coupled-cluster theory with the single, double, triple, and quadruple excitations (CCSDTQ/CBS), (ii) a new hybrid meta density functional (M06CR) specifically optimized for reactions of Criegee intermediates, and (iii) variational transition-state theory with both variable rection coordinates and optimized reaction paths, with multidimensional tunneling, and with pressure effects. For (i) we have found that quadruple excitations are required to obtain quantitative reaction barriers, and we designed new composite methods and strategies to reach CCSDTQ/CBS accuracy. The present findings show that (i) the CH2OO + HCHO reaction can make an important contribution to the sink of HCHO under wide atmospheric conditions in the gas phase and that (ii) CH2OO + (H2O)2 dominates over the CH2OO + H2O reaction below 10 km.
AB - Criegee intermediates in the atmosphere serve as oxidizing agents to initiate aerosol formation, which are particularly important for atmospheric modeling, and understanding their kinetics is one of the current outstanding challenges in climate change modeling. Because experimental kinetics are still limited, we must rely on theory for the complete picture, but obtaining absolute rates from theory is a formidable task. Here, we report the bimolecular reaction kinetics of carbonyl oxide with ammonia, hydrogen sulfide, formaldehyde, and water dimer by designing a triple-level strategy that combines (i) benchmark results close to the complete-basis limit of coupled-cluster theory with the single, double, triple, and quadruple excitations (CCSDTQ/CBS), (ii) a new hybrid meta density functional (M06CR) specifically optimized for reactions of Criegee intermediates, and (iii) variational transition-state theory with both variable rection coordinates and optimized reaction paths, with multidimensional tunneling, and with pressure effects. For (i) we have found that quadruple excitations are required to obtain quantitative reaction barriers, and we designed new composite methods and strategies to reach CCSDTQ/CBS accuracy. The present findings show that (i) the CH2OO + HCHO reaction can make an important contribution to the sink of HCHO under wide atmospheric conditions in the gas phase and that (ii) CH2OO + (H2O)2 dominates over the CH2OO + H2O reaction below 10 km.
UR - https://www.scopus.com/pages/publications/85108021385
U2 - 10.1021/jacs.1c02029
DO - 10.1021/jacs.1c02029
M3 - 文章
C2 - 34029069
AN - SCOPUS:85108021385
SN - 0002-7863
VL - 143
SP - 8402
EP - 8413
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 22
ER -
