{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T18:05:13Z","timestamp":1789754713823,"version":"4.0.1"},"reference-count":43,"publisher":"AIP Publishing","issue":"23","funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["CHE-2305293"],"award-info":[{"award-number":["CHE-2305293"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2024,6,21]]},"abstract":"<jats:p>In the present work, the electronic structure and chemical bonding of the MoC X3\u03a3\u2212 ground state and the six lowest excited states, A3\u0394, a1\u0393, b5\u03a3\u2212, c1\u0394, d1\u03a3+, and e5\u03a0, have been investigated in detail using multireference configuration interaction methods and basis sets, including relativistic effective core potentials. In addition, scalar relativistic effects have been considered in the second order Douglas\u2013Kroll\u2013Hess approximation, while spin\u2013orbit coupling has also been calculated. Five of the investigated states, X3\u03a3\u2212, A3\u0394, a1\u0393, c1\u0394, and d1\u03a3+, present quadruple \u03c32\u03c32\u03c02\u03c02 bonds. Experimentally, the predissociation threshold of MoC was measured using resonant two-photon ionization spectroscopy, allowing for a precise measurement of the dissociation energy of the ground state. Theoretically, the complete basis set limit of the calculated dissociation energy with respect to the atomic ground state products, including corrections for scalar relativistic effects, De(D0), is computed as 5.13(5.06) eV, in excellent agreement with our measured value of D0(MoC) of 5.136(5) eV. Furthermore, the calculated dissociation energies of the states having quadruple bonds with respect to their adiabatic atomic products range from 6.22 to 7.23\u00a0eV. The excited electronic states A3\u03942 and c1\u03942 are calculated to lie at 3899 and 8057 cm\u22121, also in excellent agreement with the experimental values of DaBell et al., 4002.5 and 7834 cm\u22121, respectively.<\/jats:p>","DOI":"10.1063\/5.0211422","type":"journal-article","created":{"date-parts":[[2024,6,18]],"date-time":"2024-06-18T12:02:54Z","timestamp":1718712174000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":8,"title":["Quadruple bonds in MoC: Accurate calculations and precise measurement of the dissociation energy of low-lying states of MoC"],"prefix":"10.1063","volume":"160","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6291-8461","authenticated-orcid":false,"given":"Alexandros","family":"Androutsopoulos","sequence":"first","affiliation":[{"name":"Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens 1 , Panepistimiopolis Zografou, Athens 15784, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0899-7282","authenticated-orcid":false,"given":"Demeter","family":"Tzeli","sequence":"additional","affiliation":[{"name":"Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens 1 , Panepistimiopolis Zografou, Athens 15784, Greece"},{"name":"Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation 2 , 48 Vassileos Constantinou Ave., Athens 11635, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5403-0086","authenticated-orcid":false,"given":"Kimberly H.","family":"Tomchak","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Utah 3 , Salt Lake City, Utah 84112, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2386-7315","authenticated-orcid":false,"given":"Michael D.","family":"Morse","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Utah 3 , Salt Lake City, Utah 84112, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"317","published-online":{"date-parts":[[2024,6,18]]},"reference":[{"key":"2024061812023933500_c1","doi-asserted-by":"publisher","first-page":"679","DOI":"10.1021\/cr980411m","article-title":"Electronic structure of diatomic molecules composed of a first-row transition metal and main-group Element (H\u2212F)","volume":"100","year":"2000","journal-title":"Chem. 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