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Updated: Jun 27, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Towards understanding the sign preference in binary atmospheric nucleation.

Alexey B Nadykto¹, Fangqun Yu, Jason Herb

¹Atmospheric Sciences Research Center, State University of New York at Albany, 251 Fuller Road, Albany, 12203 NY, USA. alexn@asrc.cestm.albany.edu

Physical Chemistry Chemical Physics : PCCP

|November 29, 2008

Summary

The ion sign significantly impacts binary sulfuric acid-water nucleation. Negative ions show a higher affinity for sulfuric acid, suggesting favorable nucleation for negative ions in atmospheric conditions.

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Area of Science:

Atmospheric Chemistry
Physical Chemistry
Quantum Chemistry

Background:

The role of ion sign in binary sulfuric acid-water nucleation is not fully understood.
Recent advancements in theory and instrumentation have been made.
Ion nucleation is crucial for atmospheric aerosol formation.

Purpose of the Study:

To investigate the influence of ion sign on binary sulfuric acid-water nucleation.
To elucidate the underlying mechanisms governing ion-driven nucleation.
To understand the structural and property differences of ionic clusters.

Main Methods:

Quantum-chemical calculations were performed on binary sulfuric acid-water ionic clusters.
Analysis of cluster structures and properties based on core ion sign.
Evaluation of competing factors: hydration and sulfuric acid attachment.

Main Results:

A significant ion sign effect was observed in binary nucleation.
Clusters formed over ions of different signs exhibit distinct structures and properties.
Sulfuric acid affinity is considerably higher for negative ions compared to positive ions.
Hydration is favorable for cations, while sulfuric acid attachment dominates for negative ions.

Conclusions:

The ion sign profoundly influences binary nucleation processes.
The higher affinity of sulfuric acid to negative ions suggests their preferential nucleation.
This finding has implications for understanding atmospheric aerosol formation and climate.