{
  "abstract": "Pyrophosphate is a minimal phosphoanhydride whose protonation microstates can reorganize local electrostatics and bridge geometry. We optimized 24 structures spanning five protonation states at B3LYP/ def2-SVPD with SMD water and quantified within-charge energy landscapes, structural asymmetry, Mulliken populations and orbital gaps. Most states were shallow, whereas H2P2O72- spanned 13.37 kcal mol-1. Its lowest sampled structure redistributed the two protons, contracted the P–O–P angle to 120.29°, formed two 1.89 Å intramolecular hydrogen-bond contacts and nearly equalized the phosphorus charges. Persistent asymmetric minima were 13.23–14.81 kcal mol-1 higher across B3LYP, PBE0 and ωB97X-D/ def2-TZVPD calculations; quasi-RRHO thermochemistry retained an 11.10 kcal mol-1 preference. These results identify proton placement as a major determinant of the static aqueous pyrophosphate landscape and motivate microstate screening before more expensive explicit-solvent simulations.",
  "abstract_shown": true,
  "affiliations": [
    "Chemistry",
    "Stanford Online High School, Stanford University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Aris Tsai",
      "orcid": "0009-0004-8641-7647"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a516e28ycgw2a.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008119/v1",
  "fulltext_url": null,
  "id": "a516e28ycgw2a",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008119/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": "W7204938954",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008119/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/a516e28ycgw2a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008119",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008119/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "Quantitative structure and energetics of pyrophosphate protonation microstates in implicit water",
  "title_text": "Quantitative structure and energetics of pyrophosphate protonation microstates in implicit water",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/a516e28ycgw2a",
  "venue": "ChemRxiv",
  "versions": []
}