AI Article Synopsis
- The study models the autoionization of water by analyzing the free energy of hydration for key ion species like hydroxide (OH), hydronium (HO), and Zundel (HO) ions, using both bonded and nonbonded interaction models.* -
- The models accurately reflect quantum mechanical energies to within 1%, allowing for precise calculations of free energies and atomization energies.* -
- The results indicate that the hydronium ion and its hydrated form, the Eigen cation, are the primary species involved in the autoionization of water, with calculated pH values closely matching experimental data.*
Article Abstract
We model the autoionization of water by determining the free energy of hydration of the major intermediate species of water ions. We represent the smallest ions─the hydroxide ion OH, the hydronium ion HO, and the Zundel ion HO─by bonded models and the more extended ionic structures by strong nonbonded interactions (e.g., the Eigen HO = HO + 3(HO) and the Stoyanov HO = HO + 4(HO)). Our models are faithful to the precise QM energies and their components to within 1% or less. Using the calculated free energies and atomization energies, we compute the p of pure water from first principles as a consistency check and arrive at a value within 1.3 log units of the experimental one. From these calculations, we conclude that the hydronium ion, and its hydrated state, the Eigen cation, are the dominant species in the water autoionization process.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jctc.3c01411 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!