{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,2]],"date-time":"2025-08-02T18:28:07Z","timestamp":1754159287967,"version":"3.41.2"},"reference-count":20,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,7,25]],"date-time":"2025-07-25T00:00:00Z","timestamp":1753401600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Chem."],"abstract":"<jats:p>A theoretical electronic structure calculation of the ZrH molecule is conducted via <jats:italic>ab initio<\/jats:italic> Complete Active Space Self-Consistent Field and the Multireference Configuration Interaction with Davidson correction calculation (CASSCF\/MRCI + Q). The adiabatic potential energy curves (PECs) for the 53 low-lying electronic states in the representations of <jats:sup>2s+1<\/jats:sup>\u039b<jats:sup>(+\/\u2212)<\/jats:sup> and \u03a9<jats:sup>(+\/\u2212)<\/jats:sup> for ZrH molecule have been investigated along with the internuclear distance R<jats:sub>e<\/jats:sub>, the harmonic frequency \u03c9<jats:sub>e<\/jats:sub>, the dipole moment \u03bc, the rotational constant B<jats:sub>e<\/jats:sub> and the electronic transition energy with respect to the ground state T<jats:sub>e<\/jats:sub>. are calculated. By using the canonical function approach, the vibrational energy E<jats:sub>v<\/jats:sub>, the rotational constants B<jats:sub>v<\/jats:sub>, the centrifugal constants D<jats:sub>v<\/jats:sub>, and the turning points R<jats:sub>min<\/jats:sub> and R<jats:sub>max<\/jats:sub> have been calculated up to the vibrational level v = 18. Based on the investigated data, the Franck\u2212Condon factors, the Einstein coefficient, the radiative lifetimes, and the vibrational branching ratio for the transitions X<jats:sup>2<\/jats:sup>\u0394<jats:sub>3\/2<\/jats:sub> - (1)<jats:sup>4<\/jats:sup>\u03a6<jats:sub>3\/2<\/jats:sub>, X<jats:sup>2<\/jats:sup>\u0394<jats:sub>3\/2<\/jats:sub> - (1)<jats:sup>4<\/jats:sup>\u03a6<jats:sub>5\/2<\/jats:sub>, X<jats:sup>2<\/jats:sup>\u0394<jats:sub>3\/2<\/jats:sub> - (1)<jats:sup>2<\/jats:sup>\u03a0<jats:sub>3\/2<\/jats:sub> have been calculated. The large value of the radiative lifetimes in (ms) for these transitions proves that this molecule is not a good candidate for direct laser cooling.<\/jats:p>","DOI":"10.3389\/fchem.2025.1603873","type":"journal-article","created":{"date-parts":[[2025,7,25]],"date-time":"2025-07-25T06:13:32Z","timestamp":1753424012000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Theoretical laser cooling feasibility study of ZrH molecule at the fine structure level"],"prefix":"10.3389","volume":"13","author":[{"given":"Ghina","family":"Chamieh","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lokman","family":"Awad","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nayla","family":"El-Kork","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mahmoud","family":"Korek","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,7,25]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"82","DOI":"10.1002\/jcc.21600","article-title":"Gabedit: a graphical user interface for computational chemistry software","volume":"174","author":"Allouche","year":"2011","journal-title":"J. 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