{
  "abstract": "The acid dissociation constant, commonly written as p K a , plays a key role in chemistry. However, most p K a measurements have been conducted in only a handful of solvents, resulting in data scarcity for many relevant solvent systems. Herein, we introduce the UpKast-DB, which comprises of p K a estimates for around 3,000 acids and bases in 29 solvents. We constructed UpKast-DB using a quantum-chemical method that integrates solvation free energy calculations with experimental data. Furthermore, we trained a surrogate machine learning model UpKast-ML on the computed values, allowing for rapid and accurate prediction of p K a values beyond the acids and bases presented in UpKast-DB. The quantum-chemical and machine learning methods result in RMSEs of approximately 1 p K a unit relative to experimental values, slightly higher than the typical aleatoric uncertainty of underlying experimental data, but more accurate than many existing experimental measurements (which can have uncertainties up to, and sometimes beyond, 3 p K a units). The data and modeling approaches provide a means of productively augmenting existing p K a data sources, and represent a significant step toward general determination of p K a in any solvent. The dataset and models can be found on Zenodo: doi:10.5281/zenodo.23239570",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "name": "Jonathan Wenyuan Zheng",
      "orcid": "0000-0002-4863-1325"
    },
    {
      "name": "William H. Green"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d148rq1hd9vxv.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010254/v1",
  "fulltext_url": null,
  "id": "d148rq1hd9vxv",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010254/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Advanced Chemical Physics Studies"
    ]
  ],
  "openalex": "W7221529013",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010254/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-12",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/d148rq1hd9vxv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15010254",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010254/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "UpKast: Method, Model, and Database for Large-Scale Cross-Solvent Determination of pKa Values",
  "title_text": "UpKast: Method, Model, and Database for Large-Scale Cross-Solvent Determination of pKa Values",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/d148rq1hd9vxv",
  "venue": "ChemRxiv",
  "versions": []
}