Point defects at the ice (0001) surface

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We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk c …"><meta name="keywords" content="pmid:20615938, PMC2906571, doi:10.1073/pnas.1001087107, Research Support, Non-U.S. Gov't, Matthew Watkins, Joost VandeVondele, Ben Slater, Acids, Hydrogen Bonding, Hydroxides, Ice*, Ions / chemistry, Protons, Water / chemistry, PubMed Abstract, NIH, NLM, NCBI, National Institutes of Health, National Center for Biotechnology Information, National Library of Medicine, MEDLINE"><meta name="robots" content="index,nofollow,noarchive"><meta property="og:title" content="Point defects at the ice (0001) surface - PubMed"><meta property="og:url" content="https://pubmed.ncbi.nlm.nih.gov/20615938/"><meta property="og:description" content="Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk c …"><meta property="og:image" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg"><meta property="og:image:secure_url" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg"><meta property="og:type" content="website"><meta property="og:site_name" content="PubMed"><meta name="twitter:domain" content="pubmed.ncbi.nlm.nih.gov"><meta name="twitter:card" content="summary_large_image"><meta name="twitter:title" content="Point defects at the ice (0001) surface - PubMed"><meta name="twitter:url" content="https://pubmed.ncbi.nlm.nih.gov/20615938/"><meta name="twitter:description" content="Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk c …"><meta name="twitter:image" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg">  <link rel="search" type="application/opensearchdescription+xml" href="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/opensearch.xml" title="PubMed search">  <noscript> <link rel="stylesheet" type="text/css" href="https://cdn.ncbi.nlm.nih.gov/pubmed/ed1a5a1f-b279-475e-88e3-75f261729818/core/no-script.css"> </noscript> <meta name="citation_title" content="Point defects at the ice (0001) surface"> <meta name="citation_authors" content="Watkins M;VandeVondele J;Slater B;"> <meta name="citation_date" content="07/13/2010"> <meta name="citation_publisher" content="Proc Natl Acad Sci U S A"> <meta name="citation_journal_title" content="Proceedings of the National Academy of Sciences of the United States of America"> <meta name="citation_pmid" content="20615938"> <meta name="citation_abstract_html_url" content="https://pubmed.ncbi.nlm.nih.gov/20615938/"> <meta name="citation_volume" content="107"> <meta name="citation_issue" content="28"> <meta name="citation_doi" content="10.1073/pnas.1001087107"> <meta name="citation_issn" content="1091-6490"> <link rel="canonical" href="https://pubmed.ncbi.nlm.nih.gov/20615938/" /> </head> <body > <noscript> <div class="no-script-banner" id="no-script-banner"> <div class="warning-message"> <div class="warning-message-text"> This site needs JavaScript to work properly. 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usa-input-error-message selection-validation-message"> Name must be less than 100 characters </div> </div> <div class="action-panel-control-wrap existing-collections-controls"> <label for="collections-action-panel-add-to-existing" class="action-panel-label"> Choose a collection: </label> <select id="collections-action-panel-add-to-existing" class="action-panel-selector collections-action-add-to-existing" data-ga-category="save_share" data-ga-action="select_collection" data-ga-label="($('#collections-action-add-to-existing').val() === 'Favorites') ? 'Favorites' : 'non_favorites_collection'"> </select> <div class="collections-retry-load-on-error usa-input-error-message selection-validation-message"> Unable to load your collection due to an error<br> <a href="#">Please try again</a> </div> </div> </div> <div class="action-panel-actions"> <button class="action-panel-submit" type="submit" data-loading-label="Adding..." data-pinger-ignore data-ga-category="save_share" data-ga-action="collections" data-ga-label="add"> Add </button> <button class="action-panel-cancel" aria-label="Close 'Add to Collections' panel" ref="linksrc=close_collections_panel" aria-controls="collections-action-panel" aria-expanded="false" data-ga-category="save_share" data-ga-action="collections" data-ga-label="cancel"> Cancel </button> </div> </form> </div> </div> <div id="bibliography-action-panel" class="bibliography-action-panel action-panel in-progress-dots-panel" aria-hidden="true" data-bibliography-open-panel-enabled="false" data-bibliography-open-panel-url-hash="#open-bibliography-panel"> <div class="inner-wrap"> <h3 class="action-panel-heading"> Add to My Bibliography </h3> <form id="bibliography-action-panel-form" class="bibliography-action-panel-form action-panel-content action-form action-panel-smaller-selectors" data-add-to-bibliography-max-amount="100" data-add-to-bibliography-batch-size="10" data-bibliography-delegates-url="/list-bibliography-delegates/" data-add-to-bibliography-url="/add-to-bibliography/" data-get-article-ids-by-search-url="/get-article-ids-by-search/" data-mybib-root-url="https://www.ncbi.nlm.nih.gov/myncbi/collections/mybibliography/"> <input type="hidden" name="csrfmiddlewaretoken" value="N4skSlWN2g2tHcHI5HL1E1rsQFSi9IM5aVxC77CLyQ08uqgKR5Pz8ibyTjKHMEj0"> <div class="action-panel-control-wrap bibliographies-controls"> <div class="choice-group"> <ul class="bibliographies-action-add radio-group-items"> <li> <input name="bibliography" id="my-bibliography" class="my-bibliography" type="radio" checked/> <label for="my-bibliography">My Bibliography</label> </li> </ul> </div> </div> <div class="bibliographies-retry-load-on-error usa-input-error-message selection-validation-message"> Unable to load your delegates due to an error<br> <a href="#">Please try again</a> </div> <div class="action-panel-actions"> <button class="action-panel-submit" type="submit" data-loading-label="Adding..." data-pinger-ignore> Add </button> <button class="action-panel-cancel" aria-label="Close 'Add to bibliography' panel" ref="linksrc=close_bibliography_panel" aria-controls="bibliography-action-panel" aria-expanded="false" data-ga-category="save_share" data-ga-action="mybib" data-ga-label="cancel"> Cancel </button> </div> </form> </div> </div> <div id="saved-search-action-panel" class="saved-search-action-panel action-panel " aria-hidden="true" data-saved-search-open-panel-enabled="false" data-saved-search-open-panel-url-hash="#open-saved-search-panel"> <div class="inner-wrap"> <h2 class="action-panel-heading"> Your saved search </h2> <form id="saved-search-action-panel-form" class="saved-search-action-panel-form action-panel-content action-form" data-create-saved-search-url="/create-saved-search/" data-try-search-terms-url="/try-search-term/" data-saved-search-root-url="https://www.ncbi.nlm.nih.gov/myncbi/searches/"> <input type="hidden" name="csrfmiddlewaretoken" value="N4skSlWN2g2tHcHI5HL1E1rsQFSi9IM5aVxC77CLyQ08uqgKR5Pz8ibyTjKHMEj0"> <div class="action-panel-control-wrap"> <label for="saved-search-name" class="action-panel-label saved-search-name-label required-field-asterisk"> Name of saved search: </label> <input maxlength="200" type="text" name="saved-search-name" id="saved-search-name" class="saved-search-name" value="" required pattern="[^"&=<>\/]*" title="The following characters are not allowed in the Name field: "&=<>/"> </div> <div class="action-panel-control-wrap"> <label for="saved-search-term" class="action-panel-label required-field-asterisk"> Search terms: </label> <textarea name="saved-search-term" id="saved-search-term" class="saved-search-term" required></textarea> </div> <div class="test-search-term-wrap"> <a href="#" class="try-search-term">Test search terms</a> </div> <div class="choice-group action-panel-extra-margin-top"> <span class="action-panel-label" id="fieldset-label"> Would you like email updates of new search results? </span> <fieldset id="saved-search-alert" aria-describedby="fieldset-label"> <legend class="usa-sr-only">Saved Search Alert Radio Buttons</legend> <ul class="radio-group-items"> <li> <input type="radio" id="saved-search-alert-yes" class="saved-search-alert-yes" name="saved-search-alert" value="yes" checked> <label for="saved-search-alert-yes" class="action-panel-label">Yes</label> </li> <li> <input aria-label="No radio input" type="radio" id="saved-search-alert-no" class="saved-search-alert-no" name="saved-search-alert" value="no"> <label for="saved-search-alert-no" class="action-panel-label">No</label> </li> </ul> </fieldset> </div> <div class="alert-schedule-wrap"> <div class="action-panel-control-wrap"> <label class="action-panel-label"> Email: </label> <span aria-label="Email address" id="saved-search-email" class="action-panel-label"><span class="action-panel-label-bold"></span> (<a class="myncbi-account-settings" href="https://www.ncbi.nlm.nih.gov/account/settings/">change</a>)</span> </div> <div class="action-panel-control-wrap action-panel-extra-margin-top"> <label for="saved-search-frequency" class="action-panel-label"> Frequency: </label> <select id="saved-search-frequency" class="no-border-panel-selector saved-search-frequency"> <option value="monthly">Monthly</option> <option value="weekly">Weekly</option> <option value="daily">Daily</option> </select> </div> <div class="action-panel-control-wrap saved-search-monthly-additional"> <label for="saved-search-monthly-on-day" class="action-panel-label"> Which day? </label> <select id="saved-search-monthly-on-day" class="no-border-panel-selector"> <option value="Sunday">The first Sunday</option> <option value="Monday">The first Monday</option> <option value="Tuesday">The first Tuesday</option> <option value="Wednesday">The first Wednesday</option> <option value="Thursday">The first Thursday</option> <option value="Friday">The first Friday</option> <option value="Saturday">The first Saturday</option> <option value="day">The first day</option> <option value="weekday">The first weekday</option> </select> </div> <div class="action-panel-control-wrap saved-search-weekly-additional"> <label for="saved-search-weekly-on-day" class="action-panel-label"> Which day? </label> <select id="saved-search-weekly-on-day" class="no-border-panel-selector saved-search-weekly-on-day"> <option value="Sunday">Sunday</option> <option value="Monday">Monday</option> <option value="Tuesday">Tuesday</option> <option value="Wednesday">Wednesday</option> <option value="Thursday">Thursday</option> <option value="Friday">Friday</option> <option value="Saturday">Saturday</option> </select> </div> <div class="action-panel-control-wrap"> <label for="saved-search-report" class="action-panel-label"> Report format: </label> <select id="saved-search-report" class="no-border-panel-selector saved-search-report"> <option value="DocSum">Summary</option> <option value="DocSumText">Summary (text)</option> <option value="Abstract">Abstract</option> <option value="AbstractText">Abstract (text)</option> <option value="MEDLINE">PubMed</option> </select> </div> <div class="action-panel-control-wrap"> <label for="saved-search-amount" class="action-panel-label"> Send at most: </label> <select id="saved-search-amount" class="no-border-panel-selector saved-search-amount"> <option value="1">1 item</option> <option value="5" selected>5 items</option> <option value="10">10 items</option> <option value="20">20 items</option> <option value="50">50 items</option> <option value="100">100 items</option> <option value="200">200 items</option> </select> </div> <div> <input type="checkbox" id="saved-search-send-if-no-result" class="saved-search-send-if-no-result" name="saved-search-send-if-no-result"> <label for="saved-search-send-if-no-result" class="action-panel-label smaller-checkbox"> Send even when there aren't any new results </label> </div> <div class="action-panel-control-wrap option-text-in-email-wrap"> <label for="saved-search-email-text" class="action-panel-label"> Optional text in email: </label> <textarea name="saved-search-email-text" id="saved-search-email-text" class="saved-search-email-text"></textarea> </div> </div> <div class="action-panel-actions"> <button class="action-panel-submit" type="submit" data-loading-label="Saving..." data-ga-category="save_share" data-ga-action="alert" data-ga-label="save"> Save </button> <button class="action-panel-cancel" aria-label="Close 'Your saved search' panel" ref="linksrc=close_saved_search_panel" aria-controls="saved-search-action-panel" aria-expanded="false" data-ga-category="save_share" data-ga-action="alert" data-ga-label="cancel"> Cancel </button> </div> </form> </div> </div> <div id="citation-manager-action-panel" class="citation-manager-action-panel action-panel" aria-hidden="true"> <div class="inner-wrap"> <h2 class="action-panel-heading"> Create a file for external citation management software </h2> <form id="citation-manager-action-panel-form" class="action-panel-content action-form" action="/results-export-ids/" data-by-search-action="/results-export-search-data/" data-by-ids-action="/results-export-ids/" method="post" data-by-search-method="post" data-by-ids-method="post"> <input type="hidden" name="csrfmiddlewaretoken" value="N4skSlWN2g2tHcHI5HL1E1rsQFSi9IM5aVxC77CLyQ08uqgKR5Pz8ibyTjKHMEj0"> <input name="results-format" type="hidden" value="pubmed"/> <div class="action-panel-actions"> <button class="action-panel-submit" type="submit" data-loading-label="Sending..." data-ga-category="save_share" data-ga-action="citation_manager" data-ga-label="save"> Create file </button> <button class="action-panel-cancel" aria-label="Close 'Send citations to citation manager' panel" ref="linksrc=close_citation_manager_panel" aria-controls="citation-manager-action-panel" aria-expanded="false" data-ga-category="save_share" data-ga-action="citation_manager" data-ga-label="cancel"> Cancel </button> </div> </form> </div> </div> <div id="rss-action-panel" class="rss-action-panel action-panel " aria-hidden="true"> <div class="inner-wrap"> <h2 class="action-panel-heading"> Your RSS Feed </h2> <form id="rss-action-panel-form" class="rss-action-panel-form action-panel-content action-form" data-create-rss-feed-url="/create-rss-feed-url/" data-search-form-term-value=""> <input type="hidden" name="csrfmiddlewaretoken" value="N4skSlWN2g2tHcHI5HL1E1rsQFSi9IM5aVxC77CLyQ08uqgKR5Pz8ibyTjKHMEj0"> <div class="action-panel-control-wrap"> <label for="rss-name" class="action-panel-label required-field-asterisk"> Name of RSS Feed: </label> <input maxlength="200" placeholder="Name" type="text" name="rss-name" id="rss-name" class="rss-name" value='' required pattern="[^"&=<>\/]*" title="The following characters are not allowed in the Name field: "&=<>/"> </div> <div class="rss-limit-wrap"> <div class="action-panel-control-wrap action-panel-extra-margin-top"> <label for="rss-limit" class="action-panel-label"> Number of items displayed: </label> <select id="rss-limit" class="no-border-panel-selector rss-limit"> <option value="5">5</option> <option value="10">10</option> <option value="15" selected="selected">15</option> <option value="20">20</option> <option value="50">50</option> <option value="100">100</option> </select> </div> </div> <div class="action-panel-actions"> <button class="action-panel-submit" type="submit" data-loading-label="Creating..." data-ga-category="save_share" data-ga-action="alert" data-ga-label="save"> Create RSS </button> <button class="action-panel-cancel" aria-label="Close 'Your RSS' panel" ref="linksrc=close_rss_panel" aria-controls="rss-action-panel" aria-expanded="false" data-ga-category="save_share" data-ga-action="alert" data-ga-label="cancel"> Cancel </button> </div> <div class="action-panel-control-wrap rss-link-copy-wrap"> <label for="rss-link" class="usa-sr-only">RSS Link</label> <input placeholder="Your RSS Feed Link" type="text" name="rss-link" id="rss-link" class="rss-link" title="RSS Link"> <button type="button" disabled class="rss-link-copy-button disabled" data-ga-category="save_share" data-ga-action="rss" data-ga-label="copy"> Copy </button> </div> </form> </div> </div> </div> </div> <div class="article-page" id="article-page" data-article-pmid="20615938"> <aside class="page-sidebar"> <div class="inner-wrap"> <div class="full-text-links"> <div class="full-view"> <h3 class="title"> Full text links </h3> <div class="full-text-links-list"> <a class="link-item dialog-focus" href="https://www.pnas.org/doi/10.1073/pnas.1001087107?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed" target="_blank" rel="noopener" ref="linksrc=fulltextorjournal_fulltext&is_pmc=False&PrId=4487&itool=Abstract-def&log$=linkouticon&uid=20615938&db=pubmed&nlmid=7505876" title="See full text options at Atypon" data-ga-category="full_text" data-ga-action="Atypon" data-ga-label="20615938" ><img src="https://cdn.ncbi.nlm.nih.gov/corehtml/query/egifs/https:--pnas.org-pb-assets-images-pubmed-pnas-pubmed-fulltext.png" alt="full text provider logo"><span class="text"> Atypon </span></a><a class="link-item pmc " href="https://pmc.ncbi.nlm.nih.gov/articles/pmid/20615938/" target="_blank" rel="noopener" ref="linksrc=fulltextorjournal_fulltext&is_pmc=True&PrId=3494&itool=Abstract-def&log$=linkouticon&uid=20615938&db=pubmed&nlmid=7505876" title="Free full text at PubMed Central" data-ga-category="full_text" data-ga-action="PMC" data-ga-label="20615938" ><span class="text"> 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name="csrfmiddlewaretoken" value="N4skSlWN2g2tHcHI5HL1E1rsQFSi9IM5aVxC77CLyQ08uqgKR5Pz8ibyTjKHMEj0"><div class="choice-group" role="radiogroup"><ul class="radio-group-items"><li><input type="radio" id="collections-action-dialog-new" class="collections-new" name="collections" value="new" data-ga-category="collections_button" data-ga-action="click" data-ga-label="collections_radio_new"><label for="collections-action-dialog-new">Create a new collection</label></li><li><input type="radio" id="collections-action-dialog-existing" class="collections-existing" name="collections" value="existing" checked="true" data-ga-category="collections_button" data-ga-action="click" data-ga-label="collections_radio_existing"><label for="collections-action-dialog-existing">Add to an existing collection</label></li></ul></div><div class="controls-wrapper"><div class="action-panel-control-wrap new-collections-controls"><label for="collections-action-dialog-add-to-new" class="action-panel-label required-field-asterisk"> Name your collection: </label><input type="text" name="add-to-new-collection" id="collections-action-dialog-add-to-new" class="collections-action-add-to-new" pattern="[^"&=<>\/]*" title="The following characters are not allowed in the Name field: "&=<>/" maxlength="100" data-ga-category="collections_button" data-ga-action="create_collection" data-ga-label="non_favorties_collection"><div class="collections-new-name-too-long usa-input-error-message selection-validation-message"> Name must be less than 100 characters </div></div><div class="action-panel-control-wrap existing-collections-controls"><label for="collections-action-dialog-add-to-existing" class="action-panel-label"> Choose a collection: </label><select id="collections-action-dialog-add-to-existing" class="action-panel-selector collections-action-add-to-existing" data-ga-category="collections_button" data-ga-action="select_collection" data-ga-label="($('.collections-action-add-to-existing').val() === 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'Favorites' : 'non_favorites_collection'"></select><div class="collections-retry-load-on-error usa-input-error-message selection-validation-message"> Unable to load your collection due to an error<br><a href="#">Please try again</a></div></div></div><div class="action-panel-actions"><button class="action-panel-submit" type="submit" data-loading-label="Adding..." data-pinger-ignore data-ga-category="collections_button" data-ga-action="click" data-ga-label="add"> Add </button><button class="action-panel-cancel" aria-label="Close 'Add to Collections' panel" ref="linksrc=close_collections_panel" aria-controls="collections-action-panel" aria-expanded="false" data-ga-category="collections_button" data-ga-action="click" data-ga-label="cancel"> Cancel </button></div></form></div></div></div></div><button class="more-actions-button more-actions-dialog-trigger" title="Open dialog with more actions to take" ref="linksrc=more_actions_btn"></button><div class="display-options" 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"><a class="full-name" href="/?term=Watkins+M&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Matthew Watkins">Matthew Watkins</a><sup class="affiliation-links"><span class="author-sup-separator"> </span><a class="affiliation-link" title="Department of Chemistry, University College London, 20 Gordon Street, London, United Kingdom." href="#full-view-affiliation-1" ref="linksrc=author_aff"> 1 </a></sup><span class="comma">, </span></span><span class="authors-list-item "><a class="full-name" href="/?term=VandeVondele+J&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Joost VandeVondele">Joost VandeVondele</a><span class="comma">, </span></span><span class="authors-list-item "><a class="full-name" href="/?term=Slater+B&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Ben 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"><span class="full-name">Matthew Watkins</span><span class="citation-separator"> et al.</span></span> </span> <span class="citation-journal"> Proc Natl Acad Sci U S A<span class="citation-separator">.</span> </span> <span class="date"> <time class="citation-year" datetime="2010">2010</time><span class="citation-separator">.</span> </span> </div> <div class="more-article-details-section with-display-settings"> <button class="more-article-details" id="toggle-article-details" data-alt-text="Hide details" ref="linksrc=toggle_article_details" aria-controls="full-article-details" aria-expanded="false" data-fetch-url="/20615938/long-authors/" data-id-prefix=""> <span class="title">Show details</span> </button> <div class="display-options" data-format-key="format" data-default-format-value="abstract" data-current-format-value="abstract" role="region"> <button class="trigger usa-button" title="Change format" data-ga-category="display_options" data-ga-action="display_options_dialog"> <span 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href="/?term=Watkins+M&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Matthew Watkins">Matthew Watkins</a><sup class="affiliation-links"><span class="author-sup-separator"> </span><a class="affiliation-link" title="Department of Chemistry, University College London, 20 Gordon Street, London, United Kingdom." href="#short-view-affiliation-1" ref="linksrc=author_aff"> 1 </a></sup><span class="comma">, </span></span><span class="authors-list-item "><a class="full-name" href="/?term=VandeVondele+J&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Joost VandeVondele">Joost VandeVondele</a><span class="comma">, </span></span><span class="authors-list-item "><a class="full-name" href="/?term=Slater+B&cauthor_id=20615938" ref="linksrc=author_name_link" data-ga-category="search" data-ga-action="author_link" data-ga-label="Ben Slater">Ben Slater</a></span> </div> </div> <div class="affiliations"> <h3 class="title"> Affiliation </h3> <ul class="item-list"> <li data-affiliation-id="short-view-affiliation-1" id="short-view-affiliation-1" ><sup class="key">1</sup> Department of Chemistry, University College London, 20 Gordon Street, London, United Kingdom.</li> </ul> </div> </div> <ul class="identifiers" id="short-view-identifiers"> <li> <span class="identifier pubmed"> <span class="id-label"> PMID: </span> <strong class="current-id" title="PubMed ID">20615938</strong> </span> </li> <li> <span class="identifier pmc"> <span class="id-label"> PMCID: </span> <a class="id-link" target="_blank" rel="noopener" ref="linksrc=article_id_link&article_id=PMC2906571&id_type=PMC" href="https://pmc.ncbi.nlm.nih.gov/articles/PMC2906571/" data-ga-category="full_text" data-ga-action="PMCID" > PMC2906571 </a> </span> </li> <li> <span class="identifier doi"> <span class="id-label"> DOI: </span> <a class="id-link" target="_blank" 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more actions to take" ref="linksrc=more_actions_btn"></button><div class="display-options" data-format-key="format" data-default-format-value="abstract" data-current-format-value="abstract" role="region"><button class="trigger usa-button" title="Change format" data-ga-category="display_options" data-ga-action="display_options_dialog"><span class="button-label">Display options</span></button><div class="dropdown" hidden><div class="title"> Display options </div><div class="content"><div class="format-container"><span class="option-label"> Format </span><select name="format" data-initial-value="abstract" aria-label="Display format" id="inline-actions-display-format"><option value="abstract">Abstract</option><option value="pubmed">PubMed</option><option value="pmid">PMID</option></select></div></div></div></div></div></div> <div class="abstract" id="abstract"> <h2 class="title"> Abstract </h2> <div class="abstract-content selected" id="eng-abstract"> <p> Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk crystal is smaller than its bulk formation energy. Absolute and relative segregation energies are sensitive to the surface structure of ice, especially the spatial distribution of protons associated with dangling hydrogen bonds. It is found that the basal plane surface of hexagonal ice increases the bulk concentration of Bjerrum defects, strongly favoring D-defects over L-defects. Dangling protons associated with undercoordinated water molecules are preferentially injected into the crystal bulk as Bjerrum D-defects, leading to a surface dipole that attracts hydronium ions. Aside from the disparity in segregation energies for the Bjerrum defects, we find the interactions between defect species to be very finely balanced; surface segregation energies for hydronium and hydroxide species and trapping energies of these ionic species with Bjerrum defects are equal within the accuracy of our calculations. The mobility of the ionic hydronium and hydroxide species is greatly reduced at the surface in comparison to the bulk due to surface sites with high trapping affinities. We suggest that, in pure ice samples, the surface of ice will have an acidic character due to the presence of hydronium ions. This may be important in understanding the reactivity of ice particulates in the upper atmosphere and at the boundary layer. </p> </div> </div> <p class="disclaimer" id="disclaimer"> <a href="/disclaimer/" target="_blank" ga_category="literature_resources" ga_action="disclaimer_link" ga_label="under_abstract">PubMed Disclaimer</a> </p> <div class="conflict-of-interest" id="conflict-of-interest"> <h2 class="title"> Conflict of interest statement </h2> <div class="statement"> <p xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:p1="http://pubmed.gov/pub-one">The authors declare no conflict of interest.</p> </div> </div> <div class="figures" id="figures"> <h2 class="title"> Figures </h2> <div class="figures-list" id="slides-container" itemscope itemtype="http://schema.org/ImageGallery"> <figure class="figure-item " itemscope itemtype="http://schema.org/ImageObject" itemprop="associatedMedia" data-slide-index="0" data-label-slug="fig-1"> <a class="figure-link" href="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/de4ecdab165e/pnas.1001087107fig1.jpg" itemprop="contentUrl" aria-describedby="figure-caption-0" role="button" data-image-width="450" data-image-height="162" data-image-alt="Fig. 1." data-pmc-id="PMC2906571" data-figure-id="F1"> <img class="figure-thumb" itemprop="thumbnail" id="article-image-0" src="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/7f229e14623f/pnas.1001087107fig1.gif" alt="Fig. 1." /> </a> <meta itemprop="width" itemtype="http://schema.org/ImageObject" content="450"> <meta itemprop="height" itemtype="http://schema.org/ImageObject" content="162"> <div class="figure-caption figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="caption" aria-hidden="true"> <div class="caption-wrap"> <strong class="figure-label"> <p> Fig. 1. </p> </strong> <div class="figure-caption-contents"><p> Energies for the formation of… </p></div> </div> </div> <div class="figure-caption-medium figure-caption-text" aria-hidden="true"> <strong class="figure-label"> <p> Fig. 1. </p> </strong> <div class="figure-caption-contents"><p> Energies for the formation of D and L-defects in a 6 bilayer slab… </p></div> </div> <figcaption id="figure-caption-0" class="figure-caption-full figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="description"> <strong class="figure-label"> Fig. 1. </strong> <div class="figure-caption-contents">Energies for the formation of D and L-defects in a 6 bilayer slab (see <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1001087107/-/DCSupplemental/pnas.1001087107_SI.pdf?targetid=SF2">Fig. S2</ext-link> for further details). The left hand figure shows the energies required to move a D-defect into the bulk and out to the opposite surface. The right hand figure continues the calculation and moves an L-defect across the slab to annihilate the D-defect. Missing points are caused by barrier-free relaxation of the defects to nearby layers. The reference state is the most stable ideal surface calculated.</div> </figcaption> </figure> <figure class="figure-item " itemscope itemtype="http://schema.org/ImageObject" itemprop="associatedMedia" data-slide-index="1" data-label-slug="fig-2"> <a class="figure-link" href="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/530b7478340a/pnas.1001087107fig2.jpg" itemprop="contentUrl" aria-describedby="figure-caption-1" role="button" data-image-width="428" data-image-height="231" data-image-alt="Fig. 2." data-pmc-id="PMC2906571" data-figure-id="F2"> <img class="figure-thumb" itemprop="thumbnail" id="article-image-1" src="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/9dcef60c018d/pnas.1001087107fig2.gif" alt="Fig. 2." /> </a> <meta itemprop="width" itemtype="http://schema.org/ImageObject" content="428"> <meta itemprop="height" itemtype="http://schema.org/ImageObject" content="231"> <div class="figure-caption figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="caption" aria-hidden="true"> <div class="caption-wrap"> <strong class="figure-label"> <p> Fig. 2. </p> </strong> <div class="figure-caption-contents"><p> The local environment of layer… </p></div> </div> </div> <div class="figure-caption-medium figure-caption-text" aria-hidden="true"> <strong class="figure-label"> <p> Fig. 2. </p> </strong> <div class="figure-caption-contents"><p> The local environment of layer 1 ( <i> A </i> ) D and ( <i> B… </i> </p></div> </div> <figcaption id="figure-caption-1" class="figure-caption-full figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="description"> <strong class="figure-label"> Fig. 2. </strong> <div class="figure-caption-contents">The local environment of layer 1 (<i>A</i>) D and (<i>B</i>,<i>C</i>) L-defects. In this case the D-defect has two neighboring dangling protons, while the L-defect has four. For clarity only water molecules in the upper bilayer are shown in <i>A</i>, <i>B</i>, and <i>C</i>. <i>A</i> is a view across the surface askew to the surface normal. <i>B</i> is a view atop the surface. <i>C</i> is a side view of the surface, and <i>D</i> is a multilayer cross-sectional view of the reconstructed D-defect in the third layer. The top half of the bilayer is red, the lower half blue. The oxygen atom of the defect itself is green.</div> </figcaption> </figure> <figure class="figure-item " itemscope itemtype="http://schema.org/ImageObject" itemprop="associatedMedia" data-slide-index="2" data-label-slug="fig-3"> <a class="figure-link" href="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/f948d2d6a7f8/pnas.1001087107fig3.jpg" itemprop="contentUrl" aria-describedby="figure-caption-2" role="button" data-image-width="450" data-image-height="159" data-image-alt="Fig. 3." data-pmc-id="PMC2906571" data-figure-id="F3"> <img class="figure-thumb" itemprop="thumbnail" id="article-image-2" src="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/621608348f4c/pnas.1001087107fig3.gif" alt="Fig. 3." /> </a> <meta itemprop="width" itemtype="http://schema.org/ImageObject" content="450"> <meta itemprop="height" itemtype="http://schema.org/ImageObject" content="159"> <div class="figure-caption figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="caption" aria-hidden="true"> <div class="caption-wrap"> <strong class="figure-label"> <p> Fig. 3. </p> </strong> <div class="figure-caption-contents"><p> Sampling of D (left) and… </p></div> </div> </div> <div class="figure-caption-medium figure-caption-text" aria-hidden="true"> <strong class="figure-label"> <p> Fig. 3. </p> </strong> <div class="figure-caption-contents"><p> Sampling of D (left) and L (right) formation energies as a function of… </p></div> </div> <figcaption id="figure-caption-2" class="figure-caption-full figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="description"> <strong class="figure-label"> Fig. 3. </strong> <div class="figure-caption-contents">Sampling of D (left) and L (right) formation energies as a function of number of dangling protons neighboring the site. Circles are the energies to form the near-surface defects (i.e., layer 1), triangles layer 3 defects, and red squares the energies to form the bulk-like (layer 5) defects. The different layer 3 D-defect types are detailed in the text. When the D-defect is surrounded by three protons, the formation energy in the surface layer 1 is 0.06 eV and 0.52 eV in bulk layer 5. For the case where the L-defect has three neighboring protons, the formation energy in layer 1 is 0.42 eV and 0.70 eV in layer 5.</div> </figcaption> </figure> <figure class="figure-item " itemscope itemtype="http://schema.org/ImageObject" itemprop="associatedMedia" data-slide-index="3" data-label-slug="fig-4"> <a class="figure-link" href="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/494abaf62a99/pnas.1001087107fig4.jpg" itemprop="contentUrl" aria-describedby="figure-caption-3" role="button" data-image-width="444" data-image-height="316" data-image-alt="Fig. 4." data-pmc-id="PMC2906571" data-figure-id="F4"> <img class="figure-thumb" itemprop="thumbnail" id="article-image-3" src="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/c773dbfbfa06/pnas.1001087107fig4.gif" alt="Fig. 4." /> </a> <meta itemprop="width" itemtype="http://schema.org/ImageObject" content="444"> <meta itemprop="height" itemtype="http://schema.org/ImageObject" content="316"> <div class="figure-caption figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="caption" aria-hidden="true"> <div class="caption-wrap"> <strong class="figure-label"> <p> Fig. 4. </p> </strong> <div class="figure-caption-contents"><p> Surface segregation energies of ionic… </p></div> </div> </div> <div class="figure-caption-medium figure-caption-text" aria-hidden="true"> <strong class="figure-label"> <p> Fig. 4. </p> </strong> <div class="figure-caption-contents"><p> Surface segregation energies of ionic defects at the ice surface as function of… </p></div> </div> <figcaption id="figure-caption-3" class="figure-caption-full figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="description"> <strong class="figure-label"> Fig. 4. </strong> <div class="figure-caption-contents">Surface segregation energies of ionic defects at the ice surface as function of neighboring dangling protons. H<sub>3</sub>O<sup>+</sup> squares and OH<sup>-</sup> as circles.</div> </figcaption> </figure> <figure class="figure-item " itemscope itemtype="http://schema.org/ImageObject" itemprop="associatedMedia" data-slide-index="4" data-label-slug="fig-5"> <a class="figure-link" href="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/95259e927145/pnas.1001087107fig5.jpg" itemprop="contentUrl" aria-describedby="figure-caption-4" role="button" data-image-width="488" data-image-height="156" data-image-alt="Fig. 5." data-pmc-id="PMC2906571" data-figure-id="F5"> <img class="figure-thumb" itemprop="thumbnail" id="article-image-4" src="https://cdn.ncbi.nlm.nih.gov/pmc/blobs/5938/2906571/85f26aa47e5f/pnas.1001087107fig5.gif" alt="Fig. 5." /> </a> <meta itemprop="width" itemtype="http://schema.org/ImageObject" content="488"> <meta itemprop="height" itemtype="http://schema.org/ImageObject" content="156"> <div class="figure-caption figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="caption" aria-hidden="true"> <div class="caption-wrap"> <strong class="figure-label"> <p> Fig. 5. </p> </strong> <div class="figure-caption-contents"><p> Geometry of hydronium and hydroxide… </p></div> </div> </div> <div class="figure-caption-medium figure-caption-text" aria-hidden="true"> <strong class="figure-label"> <p> Fig. 5. </p> </strong> <div class="figure-caption-contents"><p> Geometry of hydronium and hydroxide surface defects. Only the upper bilayer or water… </p></div> </div> <figcaption id="figure-caption-4" class="figure-caption-full figure-caption-text" itemtype="http://schema.org/ImageObject" itemprop="description"> <strong class="figure-label"> Fig. 5. </strong> <div class="figure-caption-contents">Geometry of hydronium and hydroxide surface defects. Only the upper bilayer or water molecules is shown for clarity. The bond length of the defect to its neighboring second layer water molecules are shown (in Å). For comparison bulk hydrogen bond distances are ≈1.70 <i>Å</i>. Top of the bilayer is coloured red while the lower layer is blue.</div> </figcaption> </figure> </div>  <div class="pswp figures-dialog" id="figures-dialog" tabindex="-1" role="dialog" aria-hidden="true" data-image-gallery-uid="article-figures" aria-label="Figures Dialog">  <div class="pswp__bg"></div>  <div class="pswp__scroll-wrap">  <div class="pswp__container"> <div class="pswp__item"></div> <div class="pswp__item"></div> <div class="pswp__item"></div> </div>  <div class="pswp__ui pswp__ui--hidden"> <div class="pswp__top-bar">  <div class="pswp__counter"></div> <button class="pswp__button pswp__button--close" title="Close (Esc)"></button> <button class="pswp__button pswp__button--share" title="Share"></button> <button class="pswp__button pswp__button--fs" title="Toggle fullscreen"></button> <button class="pswp__button pswp__button--zoom" title="Zoom in/out"></button>   <div class="pswp__preloader"> <div class="pswp__preloader__icn"> <div class="pswp__preloader__cut"> <div class="pswp__preloader__donut"></div> </div> </div> </div> </div> <div class="pswp__share-modal pswp__share-modal--hidden pswp__single-tap"> <div class="pswp__share-tooltip"></div> </div> <button class="pswp__button pswp__button--arrow--left" title="Previous (arrow left)"> </button> <button class="pswp__button pswp__button--arrow--right" title="Next (arrow right)"> </button> <div class="pswp__caption"> <div class="pswp__caption__center"></div> </div> </div> </div> </div> <div class="figure-dialog-caption"> <div class="figure-caption-link-container"> <a class="figure-caption-link" href="#">See this image and copyright information in PMC</a> </div> <div class="figure-caption-center" data-expand-title="click to show full caption" data-collapse-title="click to hide full caption"> </div> <button class="figure-caption-toggle-btn" aria-label="show full caption" data-expand-text="show full caption" data-collapse-text="hide full caption">  </button> </div> </div> <div class="similar-articles" id="similar"> <h2 class="title"> Similar articles </h2> <ul class="articles-list" id="similar-articles-list"> <li class="full-docsum"> <div class="docsum-content" style="display:inline;"> <a class="docsum-title" href="/18447454/" ref="article_id=18447454&linksrc=similar_articles_link&ordinalpos=1" data-ga-category="similar_article" data-ga-action="18447454" data-ga-label=""> Modeling equilibrium concentrations of Bjerrum and molecular point defects and their complexes in ice Ih. </a> <div class="docsum-citation full-citation"> <span class="docsum-authors full-authors">de Koning M, Antonelli A.</span> <span class="docsum-authors short-authors">de Koning M, et al.</span> <span class="docsum-journal-citation full-journal-citation">J Chem Phys. 2008 Apr 28;128(16):164502. doi: 10.1063/1.2902280.</span> <span class="docsum-journal-citation short-journal-citation">J Chem Phys. 2008.</span> <span class="citation-part">PMID: <span class="docsum-pmid">18447454</span></span> </div> </div> </li> <li class="full-docsum"> <div class="docsum-content" style="display:inline;"> <a class="docsum-title" href="/17929864/" ref="article_id=17929864&linksrc=similar_articles_link&ordinalpos=2" data-ga-category="similar_article" data-ga-action="17929864" data-ga-label=""> On the trapping of Bjerrum defects in ice Ih: the case of the molecular vacancy. </a> <div class="docsum-citation full-citation"> <span class="docsum-authors full-authors">de Koning M, Antonelli A.</span> <span class="docsum-authors short-authors">de Koning M, et al.</span> <span class="docsum-journal-citation full-journal-citation">J Phys Chem B. 2007 Nov 1;111(43):12537-42. doi: 10.1021/jp075661y. 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Polar ozone depletion (Nobel lecture) Angew Chem Int Ed Engl. 1996;35:1778–1785. </li> </ol> </li> <li> <ol class="references-and-notes-list"> <li class="skip-numbering" value="1"> Petrenko VF, Whitworth RW. Physics of ice. Oxford Univ Press; 1999. </li> </ol> </li> <li> <ol class="references-and-notes-list"> <li class="skip-numbering" value="1"> Pauling L. The structure and entropy of ice and of other crystals with some randomness of atomic arrangement. J Am Chem Soc. 1935;57:2680–2684. </li> </ol> </li> <li> <ol class="references-and-notes-list"> <li class="skip-numbering" value="1"> Bernal JD, Fowler RH. A theory of water and ionic solution, with particular reference to hydrogen and hydroxyl ions. J Chem Phys. 1933;1:515–548. </li> </ol> </li> <li> <ol class="references-and-notes-list"> <li class="skip-numbering" value="1"> Bjerrum N. Structure and properties of ice. 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href="/?term=%22Ions%2Fchemistry%22%5BMeSH%5D&sort=date&sort_order=desc" data-href="/?term=%22Ions%2Fchemistry%22%5BMeSH%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&mesh="Ions/chemistry"[MeSH]" data-ga-category="search" data-ga-action="mesh_term" data-ga-label="Ions / chemistry"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh?term=Ions" data-ga-category="search_mesh" data-ga-action="mesh_term_link" data-ga-label="Ions / chemistry"> Search in MeSH </a></li><li><a class="add-to-search-link dropdown-block-link" ref="linksrc=add_to_search_link" role="button" data-search-term=""Ions/chemistry"[MeSH]" data-ga-category="search" data-ga-action="add_to_search" data-ga-label=""Ions/chemistry"[MeSH]" href="#"> Add to Search </a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link" aria-label="Toggle dropdown menu for keyword Protons" tabindex="0" aria-controls="keyword-actions-mesh-terms-5" aria-expanded="false" data-pinger-ignore> Protons </button><div id="keyword-actions-mesh-terms-5" class="keyword-actions-dropdown dropdown dropdown-container" hidden aria-label="Dropdown menu for keyword Protons"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link" href="/?term=%22Protons%22%5BMeSH%5D&sort=date&sort_order=desc" data-href="/?term=%22Protons%22%5BMeSH%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&mesh="Protons"[MeSH]" data-ga-category="search" data-ga-action="mesh_term" data-ga-label="Protons"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh?term=Protons" data-ga-category="search_mesh" data-ga-action="mesh_term_link" 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href="/?term=%22Water%2Fchemistry%22%5BMeSH%5D&sort=date&sort_order=desc" data-href="/?term=%22Water%2Fchemistry%22%5BMeSH%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&mesh="Water/chemistry"[MeSH]" data-ga-category="search" data-ga-action="mesh_term" data-ga-label="Water / chemistry"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh?term=Water" data-ga-category="search_mesh" data-ga-action="mesh_term_link" data-ga-label="Water / chemistry"> Search in MeSH </a></li><li><a class="add-to-search-link dropdown-block-link" ref="linksrc=add_to_search_link" role="button" data-search-term=""Water/chemistry"[MeSH]" data-ga-category="search" data-ga-action="add_to_search" data-ga-label=""Water/chemistry"[MeSH]" href="#"> Add to Search </a></li></ul></div></div></div></li></ul> </div> <div id="substances" class="substances keywords-section"> <h2 class="title"> Substances </h2> <ul class="keywords-list"><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link" aria-label="Toggle dropdown menu for keyword Acids" tabindex="0" aria-controls="keyword-actions-substances-0" aria-expanded="false" data-pinger-ignore> Acids </button><div id="keyword-actions-substances-0" class="keyword-actions-dropdown dropdown dropdown-container" hidden aria-label="Dropdown menu for keyword Acids"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link" href="/?term=%22Acids%22%5Bnm%5D&sort=date&sort_order=desc" data-href="/?term=%22Acids%22%5Bnm%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&keyword="Acids"[nm]" data-ga-category="search" data-ga-action="substance" data-ga-label="Acids"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" 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class="search-in-pubmed-link dropdown-block-link" href="/?term=%22Hydroxides%22%5Bnm%5D&sort=date&sort_order=desc" data-href="/?term=%22Hydroxides%22%5Bnm%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&keyword="Hydroxides"[nm]" data-ga-category="search" data-ga-action="substance" data-ga-label="Hydroxides"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh?term=%22Hydroxides%22" data-ga-category="search_mesh" data-ga-action="substance_link" data-ga-label="Hydroxides"> Search in MeSH </a></li><li><a class="add-to-search-link dropdown-block-link" ref="linksrc=add_to_search_link" role="button" data-search-term=""Hydroxides"[nm]" data-ga-category="search" data-ga-action="add_to_search" data-ga-label=""Hydroxides"[nm]" href="#"> Add to Search </a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button 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aria-expanded="false" data-pinger-ignore> Protons </button><div id="keyword-actions-substances-4" class="keyword-actions-dropdown dropdown dropdown-container" hidden aria-label="Dropdown menu for keyword Protons"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link" href="/?term=%22Protons%22%5Bnm%5D&sort=date&sort_order=desc" data-href="/?term=%22Protons%22%5Bnm%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&keyword="Protons"[nm]" data-ga-category="search" data-ga-action="substance" data-ga-label="Protons"> Search in PubMed </a></li><li><a class="search-in-mesh-link dropdown-block-link" ref="linksrc=search_in_mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh?term=%22Protons%22" data-ga-category="search_mesh" data-ga-action="substance_link" data-ga-label="Protons"> Search in MeSH </a></li><li><a class="add-to-search-link dropdown-block-link" ref="linksrc=add_to_search_link" role="button" data-search-term=""Protons"[nm]" data-ga-category="search" data-ga-action="add_to_search" data-ga-label=""Protons"[nm]" href="#"> Add to Search </a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link" aria-label="Toggle dropdown menu for keyword Water" tabindex="0" aria-controls="keyword-actions-substances-5" aria-expanded="false" data-pinger-ignore> Water </button><div id="keyword-actions-substances-5" class="keyword-actions-dropdown dropdown dropdown-container" hidden aria-label="Dropdown menu for keyword Water"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link" href="/?term=%22Water%22%5Bnm%5D&sort=date&sort_order=desc" data-href="/?term=%22Water%22%5Bnm%5D&sort=date&sort_order=desc" ref="linksrc=search_in_pubmed_keyword_link&keyword="Water"[nm]" 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