Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy

<!DOCTYPE html>     <html class="no-js" lang="en">  <head> <title>Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy - ADS</title>  <link rel="apple-touch-icon" sizes="180x180" href="//styles/favicon/apple-touch-icon.png" /> <link rel="icon" type="image/png" sizes="32x32" href="//styles/favicon/favicon-32x32.png" /> <link rel="icon" type="image/png" sizes="16x16" href="//styles/favicon/favicon-16x16.png" /> <link rel="manifest" href="//styles/favicon/site.webmanifest" /> <link rel="mask-icon" href="//styles/favicon/safari-pinned-tab.svg" color="#5bbad5" /> <meta name="apple-mobile-web-app-title" content="ADS" /> <meta name="application-name" content="ADS" /> <meta name="msapplication-TileColor" content="#ffc40d" /> <meta name="theme-color" content="#ffffff" />   <script>(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-NT2453N');</script>  <link rel="stylesheet" href="/styles/css/styles.css"> <meta name="robots" content="noarchive"> <link rel="canonical" href="http://ui.adsabs.harvard.edu/abs/2015JMoSp.311...76D/abstract"/> <meta name="description" content="BeH is one of the most important benchmark systems for ab initio methods and for studying Born-Oppenheimer breakdown. However the best empirical potential and best ab initio potential for the ground electronic state to date give drastically different predictions in the long-range region between where the highest measurements have been made, and the dissociation energy; a region which is about ∼1000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeH, ∼ 3000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeD, and ∼13 000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeT. Improved empirical potentials and Born-Oppenheimer breakdown corrections have now been built in this work for the ground electronic states X (1<SUP>2</SUP>Σ<SUP>+</SUP>) of all three isotopologues. The predicted dissociation energy for <SUP>9</SUP>BeH from the new empirical potential is now in agreement with the current best ab initio prediction in all 5 digits of the former's precision, while the previous best empirical potential was in disagreement by 74 cm<SUP>-1</SUP>. The previous best empirical potential predicted the existence of unobserved vibrational levels for all three isotopologues, and the current best ab initio study also predicted the existence of all of these levels, and 7 more in total. With the exception of two, the present empirical potential agrees with the existence of all of the ab initio potentials' extra levels not predicted by the earlier empirical potential. With one exception, all energy spacings between vibrational energy levels for which measurements have been made, are predicted with an agreement of better than 1 cm<SUP>-1</SUP> between the new empirical potential and the current best ab initio potential, but some predictions for unobserved levels are still in great disagreement, and the equilibrium bond lengths are different by orders of magnitude.">  <meta property="og:type" content="article"> <meta property="og:title" content="Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy"> <meta property="og:site_name" content="ADS"> <meta property="og:description" content="BeH is one of the most important benchmark systems for ab initio methods and for studying Born-Oppenheimer breakdown. However the best empirical potential and best ab initio potential for the ground electronic state to date give drastically different predictions in the long-range region between where the highest measurements have been made, and the dissociation energy; a region which is about ∼1000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeH, ∼ 3000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeD, and ∼13 000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeT. Improved empirical potentials and Born-Oppenheimer breakdown corrections have now been built in this work for the ground electronic states X (1<SUP>2</SUP>Σ<SUP>+</SUP>) of all three isotopologues. The predicted dissociation energy for <SUP>9</SUP>BeH from the new empirical potential is now in agreement with the current best ab initio prediction in all 5 digits of the former's precision, while the previous best empirical potential was in disagreement by 74 cm<SUP>-1</SUP>. The previous best empirical potential predicted the existence of unobserved vibrational levels for all three isotopologues, and the current best ab initio study also predicted the existence of all of these levels, and 7 more in total. With the exception of two, the present empirical potential agrees with the existence of all of the ab initio potentials' extra levels not predicted by the earlier empirical potential. With one exception, all energy spacings between vibrational energy levels for which measurements have been made, are predicted with an agreement of better than 1 cm<SUP>-1</SUP> between the new empirical potential and the current best ab initio potential, but some predictions for unobserved levels are still in great disagreement, and the equilibrium bond lengths are different by orders of magnitude."> <meta property="og:url" content="https://ui.adsabs.harvard.edu/abs/2015JMoSp.311...76D/abstract"> <meta property="og:image" content="https://ui.adsabs.harvard.edu/styles/img/transparent_logo.svg"> <meta property="article:published_time" content="05/2015"> <meta property="article:author" content="Dattani, Nikesh S.">  <meta name="citation_journal_title" content="Journal of Molecular Spectroscopy"> <meta name="citation_authors" content="Dattani, Nikesh S."> <meta name="citation_title" content="Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy"> <meta name="citation_date" content="05/2015"> <meta name="citation_volume" content="311"> <meta name="citation_firstpage" content="76"> <meta name="citation_doi" content="10.1016/j.jms.2014.09.005"> <meta name="citation_issn" content="0022-2852"> <meta name="citation_language" content="en"> <meta name="citation_keywords" content="Ultra-high precision"> <meta name="citation_keywords" content="Interstellar chemistry &amp; astrochemistry"> <meta name="citation_keywords" content="Fundamental molecules"> <meta name="citation_keywords" content="Early universe chemistry"> <meta name="citation_keywords" content="Big Bang physics"> <meta name="citation_keywords" content="Potentiology &amp; potential energy curves and surfaces"> <meta name="citation_keywords" content="Halo nucleonic molecules"> <meta name="citation_keywords" content="Theory vs experiment"> <meta name="citation_keywords" content="Exoplanet atmosphere"> <meta name="citation_keywords" content="Cool stars"> <meta name="citation_keywords" content="Stellar chemistry and the Sun"> <meta name="citation_keywords" content="Isotope effect"> <meta name="citation_keywords" content="Dispersion constants"> <meta name="citation_keywords" content="Physics - Chemical Physics"> <meta name="citation_keywords" content="Astrophysics - Solar and Stellar Astrophysics"> <meta name="citation_keywords" content="Physics - Atomic and Molecular Clusters"> <meta name="citation_abstract_html_url" content="https://ui.adsabs.harvard.edu/abs/2015JMoSp.311...76D/abstract"> <meta name="citation_publication_date" content="05/2015"> <meta name="citation_lastpage" content="83" /> <meta name="citation_arxiv_id" content="arXiv:1408.3301" /> <link title="schema(PRISM)" rel="schema.prism" href="http://prismstandard.org/namespaces/1.2/basic/" /> <meta name="prism.publicationDate" content="05/2015" /> <meta name="prism.publicationName" content="JMoSp" /> <meta name="prism.issn" content="0022-2852" /> <meta name="prism.volume" content="311" /> <meta name="prism.startingPage" content="76" /> <meta name="prism.endingPage" content="83" /> <link title="schema(DC)" rel="schema.dc" href="http://purl.org/dc/elements/1.1/" /> <meta name="dc.identifier" content="doi:10.1016/j.jms.2014.09.005" /> <meta name="dc.date" content="05/2015" /> <meta name="dc.source" content="JMoSp" /> <meta name="dc.title" content="Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy" /> <meta name="dc.creator" content="Dattani, Nikesh S.">  <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:description" content="BeH is one of the most important benchmark systems for ab initio methods and for studying Born-Oppenheimer breakdown. However the best empirical potential and best ab initio potential for the ground electronic state to date give drastically different predictions in the long-range region between where the highest measurements have been made, and the dissociation energy; a region which is about ∼1000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeH, ∼ 3000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeD, and ∼13 000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeT. Improved empirical potentials and Born-Oppenheimer breakdown corrections have now been built in this work for the ground electronic states X (1<SUP>2</SUP>Σ<SUP>+</SUP>) of all three isotopologues. The predicted dissociation energy for <SUP>9</SUP>BeH from the new empirical potential is now in agreement with the current best ab initio prediction in all 5 digits of the former's precision, while the previous best empirical potential was in disagreement by 74 cm<SUP>-1</SUP>. The previous best empirical potential predicted the existence of unobserved vibrational levels for all three isotopologues, and the current best ab initio study also predicted the existence of all of these levels, and 7 more in total. With the exception of two, the present empirical potential agrees with the existence of all of the ab initio potentials' extra levels not predicted by the earlier empirical potential. With one exception, all energy spacings between vibrational energy levels for which measurements have been made, are predicted with an agreement of better than 1 cm<SUP>-1</SUP> between the new empirical potential and the current best ab initio potential, but some predictions for unobserved levels are still in great disagreement, and the equilibrium bond lengths are different by orders of magnitude."/> <meta name="twitter:title" content="Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy"/> <meta name="twitter:site" content="@adsabs"/> <meta name="twitter:domain" content="ADS"/> <meta name="twitter:image:src" content="https://ui.adsabs.harvard.edu/styles/img/transparent_logo.svg"/> <meta name="twitter:creator" content="@adsabs"/> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"> <base href="/"> <style> .btn-full-ads { color: #fff !important; background-color: #1a1a1a !important; border-color: #1a1a1a !important; 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However the best empirical potential and best ab initio potential for the ground electronic state to date give drastically different predictions in the long-range region between where the highest measurements have been made, and the dissociation energy; a region which is about ∼1000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeH, ∼ 3000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeD, and ∼13 000 cm<SUP>-1</SUP> for <SUP>9</SUP>BeT. Improved empirical potentials and Born-Oppenheimer breakdown corrections have now been built in this work for the ground electronic states X (1<SUP>2</SUP>Σ<SUP>+</SUP>) of all three isotopologues. The predicted dissociation energy for <SUP>9</SUP>BeH from the new empirical potential is now in agreement with the current best ab initio prediction in all 5 digits of the former's precision, while the previous best empirical potential was in disagreement by 74 cm<SUP>-1</SUP>. The previous best empirical potential predicted the existence of unobserved vibrational levels for all three isotopologues, and the current best ab initio study also predicted the existence of all of these levels, and 7 more in total. With the exception of two, the present empirical potential agrees with the existence of all of the ab initio potentials' extra levels not predicted by the earlier empirical potential. With one exception, all energy spacings between vibrational energy levels for which measurements have been made, are predicted with an agreement of better than 1 cm<SUP>-1</SUP> between the new empirical potential and the current best ab initio potential, but some predictions for unobserved levels are still in great disagreement, and the equilibrium bond lengths are different by orders of magnitude. </p> </div> <br> <dl class="s-abstract-dl-horizontal"> <dt>Publication:</dt> <dd> <div id="article-publication">Journal of Molecular Spectroscopy</div> </dd> <dt>Pub Date:</dt> <dd>May 2015</dd> <dt>DOI:</dt> <dd> <p class="doi-p"> <a href="/link_gateway/2015JMoSp.311...76D/doi:10.1016/j.jms.2014.09.005" target="_blank" rel="noreferrer noopener">10.1016/j.jms.2014.09.005</a> <i class="fa fa-external-link"></i> </p> <p class="doi-p"> <a href="/link_gateway/2015JMoSp.311...76D/doi:10.48550/arXiv.1408.3301" target="_blank" rel="noreferrer noopener">10.48550/arXiv.1408.3301</a> <i class="fa fa-external-link"></i> </p> </dd> <dt>arXiv:</dt> <dd> <span> <a href="/link_gateway/2015JMoSp.311...76D/arXiv:1408.3301" target="_blank" rel="noreferrer noopener">arXiv:1408.3301</a> <i class="fa fa-external-link"></i> </span> </dd> <dt>Bibcode:</dt> <dd> <a href="/abs/2015JMoSp.311...76D/abstract"> 2015JMoSp.311...76D </a> <i class="icon-help" title="The bibcode is assigned by the ADS as a unique identifier for the paper."></i> </dd> <dt>Keywords:</dt> <dd> <ul class="list-inline"> <li>Ultra-high precision;</li> <li>Interstellar chemistry &amp; astrochemistry;</li> <li>Fundamental molecules;</li> <li>Early universe chemistry;</li> <li>Big Bang physics;</li> <li>Potentiology &amp; potential energy curves and surfaces;</li> <li>Halo nucleonic molecules;</li> <li>Theory vs experiment;</li> <li>Exoplanet atmosphere;</li> <li>Cool stars;</li> <li>Stellar chemistry and the Sun;</li> <li>Isotope effect;</li> <li>Dispersion constants;</li> <li>Physics - Chemical Physics;</li> <li>Astrophysics - Solar and Stellar Astrophysics;</li> <li>Physics - Atomic and Molecular Clusters</li> </ul> </dd> <dt>E-Print:</dt> <dd> Feedback encouraged. 9 Pages, 4 Figures, 4 Tables. 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Beryllium monohydride (BeH): Where we are now, after 86 years of spectroscopy - ADS