Understanding the solvent effect on ion-pair dissociation at the air-water interface by machine learning interatomic potential

Understanding the solvent effect on ion-pair dissociation at the air-water interface by machine learning interatomic potential | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Understanding the solvent effect on ion-pair dissociation at the air-water interface by machine learning interatomic potential Mirza Galib, Mohammad Badhon This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8715052/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Solvent interactions play a key role in ion-pair formation and dissociation at the air–water interface, but capturing these effects requires ab initio accuracy and explicit solvent coordinate, which are often beyond standard DFT simulations. Machine Learning Interatomic Potentials (MLIPs) offer a promising solution, though generating diverse training datasets for MLIP training remains challenging. Here, we show that initial sampling by classical simulations followed by ab initio optimization can efficiently produce MLIPs capable of capturing the influence of collective solvent coordinate. Using Ca2+..SO42– dissociation as a model, we demonstrate that an accurate estimation of dissociation free energy and kinetics requires an explicit solvent coordinate and ab initio level of theory. In contrast to the classical force field, an ab initio interactions stabilize the solvent shared ion-pair at the air-water interface by 3 kcal/mol. Relative to the bulk, interfacial solvation increases dissociation free energy and slows the dissociation rate, while formation energy barriers remain largely unchanged. These results show that MLIPs can reliably capture solvent effects with ab initio accuracy for ion-pair thermodynamics and kinetics. Physical sciences/Chemistry/Physical chemistry/Chemical physics Physical sciences/Chemistry/Physical chemistry/Reaction kinetics and dynamics Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8715052","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":581852770,"identity":"ce5859e6-dc9e-404b-8843-a576fcd40b1c","order_by":0,"name":"Mirza Galib","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYDACZjBpwWPA3gCkDSyI1iLBY8BzAKRFgmi7JICKEyAMgkC3nf0B45caCRlzyedXN/wokGDgb+9OwKvF7DBDArPMMQkey9k5ZTd7gA6TOHN2AyEtB5gl2IB+uZ2TdoPHAOTCXEJaGBuYJf4Btdw8k3bzD3FamBkYP7YBtdxgP3abSFvYGA4z9gH90pPDdlvGQIKHsF/OH3/48Mc3G3tz9uPPbr75YyPH396LXwsIHOYBUzwGYJKgchBg/AGm2B8QpXoUjIJRMApGHgAALIJBzeztLgUAAAAASUVORK5CYII=","orcid":"","institution":"Howard University","correspondingAuthor":true,"prefix":"","firstName":"Mirza","middleName":"","lastName":"Galib","suffix":""},{"id":581852771,"identity":"9472cef5-191f-4bd1-9b70-3c3fe263be0f","order_by":1,"name":"Mohammad Badhon","email":"","orcid":"","institution":"Howard University","correspondingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"","lastName":"Badhon","suffix":""}],"badges":[],"createdAt":"2026-01-28 01:20:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8715052/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8715052/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103506577,"identity":"a9d17a94-57aa-4e87-a971-ab906de9ddf4","added_by":"auto","created_at":"2026-02-26 13:37:44","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1313795,"visible":true,"origin":"","legend":"Article File","description":"","filename":"mainarticlemirza2.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8715052/v1_covered_d5ba6c99-4d60-4c35-b90e-1af4371e9273.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Understanding the solvent effect on ion-pair dissociation at the air-water\r\ninterface by machine learning interatomic potential","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8715052/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8715052/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Solvent interactions play a key role in ion-pair formation and dissociation at the air–water interface, but capturing these effects requires ab initio accuracy and explicit solvent coordinate, which are often beyond standard DFT simulations. 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