Title

Calculating Reliable Gibbs Free Energies for Formation of Gas-Phase Clusters that Are Critical for Atmospheric Chemistry: (H2SO4)3

ACS Citation

Kurfman, L.A.; Odbadrakh, T.T.; Shields, G.C. "Calculating Reliable Gibbs Free Energies for Formation of Gas-Phase Clusters that Are Critical for Atmospheric Chemistry: (H2SO4)3", J. Phys. Chem. A 2021, 125, 15, 3169-3176.

Abstract

The effects of atmospheric aerosols on our climate are one of the biggest uncertainties in global climate models. Calculating the pathway for the formation of pre-nucleation clusters that become aerosols is challenging, requiring a comprehensive analysis of configurational space and highly accurate Gibbs free energy calculations. We identified a large set of minimum energy configurations of (H2SO4)3 using a sampling technique based on a genetic algorithm and a stepwise density functional theory (DFT) approach and computed the thermodynamics of formation of these configurations with more accurate wavefunction-based electronic energies computed on the DFT geometries. The DLPNO-CCSD(T) methods always return more positive energies compared to the DFT energies. Within the DLPNO-CCSD(T) methods, extrapolating to the complete basis set limit gives more positive free energies compared to explicitly correlated single-point energies. The CBS extrapolation was shown to be robust as both the 4-5 inverse polynomial and Riemann zeta function schemes were within chemical accuracy of one another.

Source Name

Journal of Physical Chemistry A

Publication Date

Spring 4-7-2021

Volume

125

Issue

15

Page(s)

3169-3176

Document Type

Citation

Citation Type

Article

Comments

50 free reprints available with this link:

https://pubs.acs.org/articlesonrequest/AOR-3KYRMBMAF7FAYMH9R7TC

Share

COinS