{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T07:36:28Z","timestamp":1778052988894,"version":"3.51.4"},"reference-count":87,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,2,13]],"date-time":"2023-02-13T00:00:00Z","timestamp":1676246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["OIA-1757220"],"award-info":[{"award-number":["OIA-1757220"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["NNX17AH15G"],"award-info":[{"award-number":["NNX17AH15G"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["18-XRP18_2-0029"],"award-info":[{"award-number":["18-XRP18_2-0029"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000104","name":"NASA","doi-asserted-by":"publisher","award":["OIA-1757220"],"award-info":[{"award-number":["OIA-1757220"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000104","name":"NASA","doi-asserted-by":"publisher","award":["NNX17AH15G"],"award-info":[{"award-number":["NNX17AH15G"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000104","name":"NASA","doi-asserted-by":"publisher","award":["18-XRP18_2-0029"],"award-info":[{"award-number":["18-XRP18_2-0029"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]},{"name":"University of Mississippi","award":["OIA-1757220"],"award-info":[{"award-number":["OIA-1757220"]}]},{"name":"University of Mississippi","award":["NNX17AH15G"],"award-info":[{"award-number":["NNX17AH15G"]}]},{"name":"University of Mississippi","award":["18-XRP18_2-0029"],"award-info":[{"award-number":["18-XRP18_2-0029"]}]},{"name":"Mississippi Center for Supercomputing Research","award":["OIA-1757220"],"award-info":[{"award-number":["OIA-1757220"]}]},{"name":"Mississippi Center for Supercomputing Research","award":["NNX17AH15G"],"award-info":[{"award-number":["NNX17AH15G"]}]},{"name":"Mississippi Center for Supercomputing Research","award":["18-XRP18_2-0029"],"award-info":[{"award-number":["18-XRP18_2-0029"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>New high-level ab initio quartic force field (QFF) methods are explored which provide spectroscopic data for the electronically excited states of the carbon monoxide, water, and formaldehyde cations, sentinel species for expanded, recent cometary spectral analysis. QFFs based on equation-of-motion ionization potential (EOM-IP) with a complete basis set extrapolation and core correlation corrections provide assignment for the fundamental vibrational frequencies of the A\u02dc2B1 and B\u02dc2A1 states of the formaldehyde cation; only three of these frequencies have experimental assignment available. Rotational constants corresponding to these vibrational excitations are also provided for the first time for all electronically excited states of both of these molecules. EOM-IP-CCSDT\/CcC computations support tentative re-assignment of the \u03bd1 and \u03bd3 frequencies of the B\u02dc2B2 state of the water cation to approximately 2409.3 cm\u22121 and 1785.7 cm\u22121, respectively, due to significant disagreement between experimental assignment and all levels of theory computed herein, as well as work by previous authors. The EOM-IP-CCSDT\/CcC QFF achieves agreement to within 12 cm\u22121 for the fundamental vibrational frequencies of the electronic ground state of the water cation compared to experimental values and to the high-level theoretical benchmarks for variationally-accessible states. Less costly EOM-IP based approaches are also explored using approximate triples coupled cluster methods, as well as electronically excited state QFFs based on EOM-CC3 and the previous (T)+EOM approach. The novel data, including vibrationally corrected rotational constants for all states studied herein, provided by these computations should be useful in clarifying comet evolution or other remote sensing applications in addition to fundamental spectroscopy.<\/jats:p>","DOI":"10.3390\/molecules28041782","type":"journal-article","created":{"date-parts":[[2023,2,14]],"date-time":"2023-02-14T01:41:06Z","timestamp":1676338866000},"page":"1782","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Complete, Theoretical Rovibronic Spectral Characterization of the Carbon Monoxide, Water, and Formaldehyde Cations"],"prefix":"10.3390","volume":"28","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4038-8615","authenticated-orcid":false,"given":"Megan C.","family":"Davis","sequence":"first","affiliation":[{"name":"Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38677-1848, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2458-5050","authenticated-orcid":false,"given":"Xinchuan","family":"Huang","sequence":"additional","affiliation":[{"name":"SETI Institute, Mountain View, CA 94043, USA"},{"name":"MS 245-6, NASA Ames Research Center, Moffett Field, CA 94035, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4716-8225","authenticated-orcid":false,"given":"Ryan C.","family":"Fortenberry","sequence":"additional","affiliation":[{"name":"Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38677-1848, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"066901","DOI":"10.1088\/0034-4885\/75\/6\/066901","article-title":"Ion Chemistry in Space","volume":"75","author":"Larsson","year":"2012","journal-title":"Rep. Prog. Phys."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"6","DOI":"10.3847\/1538-4365\/ac0cfd","article-title":"Knowledge Gaps in the Cometary Spectra of Oxygen-Bearing Molecular Cations","volume":"256","author":"Fortenberry","year":"2021","journal-title":"Astrophys. J. Suppl. Ser."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"L73","DOI":"10.1086\/311869","article-title":"Unidentified Molecular Bands in the Plasma Tail of Comet Hyakutake (C\/1996 B2)","volume":"512","author":"Wyckoff","year":"1999","journal-title":"Astrophys. J."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"130","DOI":"10.3847\/0004-6256\/152\/5\/130","article-title":"Changes in the Physical Environment of the Inner Coma of 67P\/Churyumov-Gerasimenko with Decreasing Heliocentric Distance","volume":"152","author":"Bodewits","year":"2016","journal-title":"Astron. J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"A27","DOI":"10.1051\/0004-6361\/201936775","article-title":"ROSINA Ion Zoo at Comet 67P","volume":"642","author":"Beth","year":"2020","journal-title":"Astron. Astrophys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.1086\/118090","article-title":"A High-Resolution Catalog of Cometary Emission Lines","volume":"112","author":"Brown","year":"1996","journal-title":"Astron. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1086\/133931","article-title":"High-Resolution Optical Spectra of the Head of the Comet C\/1996 B2 (Hyakutake)","volume":"109","author":"Morrison","year":"1997","journal-title":"Publ. Astron. Soc. Pac."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1086\/318314","article-title":"A Survey of Organic Volatile Species in Comet C\/1999 H1 (Lee) Using NIRSPEC at the Keck Observatory","volume":"546","author":"Mumma","year":"2001","journal-title":"Astrophys. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1006\/icar.2002.6850","article-title":"A High Spectral Resolution Atlas of Comet 122P\/de Vico","volume":"157","author":"Cochran","year":"2002","journal-title":"Icarus"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1051\/0004-6361:20054323","article-title":"Catalog of the Emission Lines in the Visible Spectrum of Comet 153P\/Ikeya-Zhang","volume":"461","author":"Cremonese","year":"2006","journal-title":"Astron. Astrophys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"L183","DOI":"10.1086\/342533","article-title":"Revised Fluorescence Efficiencies of Cometary NH2: Ammonia Abundance in Comets","volume":"574","author":"Kawakita","year":"2002","journal-title":"Astrophys. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1016\/j.icarus.2012.05.023","article-title":"A High-Resolution Infrared Spectral Survey of 103P\/Hartley 2 on the Night of the EPOXI Closest Approach","volume":"222","author":"Vervack","year":"2013","journal-title":"Icarus"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"L8","DOI":"10.1051\/0004-6361\/201936959","article-title":"2I\/Borisov: A C2-Depleted Interstellar Comet","volume":"631","author":"Opitom","year":"2019","journal-title":"Astron. Astrophys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"154107","DOI":"10.1063\/1.1884600","article-title":"Equation-of-Motion Coupled-Cluster Methods for Ionized States with an Approximate Treatment of Triple Excitations","volume":"122","author":"Bomble","year":"2005","journal-title":"J. Chem. Phys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.comptc.2011.10.002","article-title":"MRCI Study of Potential Energy Curves, Spectroscopic and Molecular Properties of the CO+ Cation","volume":"978","author":"Shi","year":"2011","journal-title":"Comput. Theor. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2165","DOI":"10.1021\/ct300194x","article-title":"Geometries and Vibrational Frequencies of Small Radicals: Performance of Coupled Cluster and More Approximate Methods","volume":"8","author":"Tentscher","year":"2012","journal-title":"J. Chem. Theory Comput."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.jqsrt.2019.05.030","article-title":"Fourier-Transform Spectroscopy of the A2\u03a0i- X2\u03b1+ System in CO+ and Depurturbation Analysis of the A2\u03a0i(\u03bd = 0, 1) Levels","volume":"234","author":"Hakalla","year":"2019","journal-title":"J. Quant. Spectrosc. Rad. Transfer"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1063\/1.2436891","article-title":"Experimental Vibrational Zero-Point Energies: Diatomic Molecules","volume":"36","author":"Irikura","year":"2007","journal-title":"J. Phys. Chem. Ref. Data"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"8809","DOI":"10.1063\/1.461215","article-title":"Observation of the Visible Absorption Spectrum of H2O+","volume":"95","author":"Das","year":"1991","journal-title":"J. Chem. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6928","DOI":"10.1063\/1.451379","article-title":"Molecular Beam Photoelectron Spectroscopy and Femtosecond Intramolecular Dynamics of Oxoniumyl(H2O+) and Oxoniumyl-d2(D2O+)","volume":"85","author":"Reutt","year":"1986","journal-title":"J. Chem. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5645","DOI":"10.1063\/1.474326","article-title":"The A 2A1-X 2B1 Transition of H2O+ in the Near Infrared Region","volume":"107","author":"Huet","year":"1997","journal-title":"J. Chem. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/S0022-2852(03)00016-X","article-title":"Observation and Analysis of Two Subbands in the Absorption Spectrum of H2O+","volume":"219","author":"Wu","year":"2003","journal-title":"J. Mol. Spectrosc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.jms.2004.02.011","article-title":"Vibronic Transition Moments and Line Intensities for H2O+","volume":"225","author":"Wu","year":"2004","journal-title":"J. Mol. Spectrosc."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Lauzin, C., Gans, B., and Merkt, F. (2017). High-Resolution Photoelectron-Spectroscopic Investigation of the H2O+ Cation in its \u00c3+ Electronic State. arXiv.","DOI":"10.1080\/00268976.2016.1231352"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.chemphys.2008.12.009","article-title":"Threshold Photoelectron Spectroscopy of H2O and D2O over the Photon Energy Range 12\u201340 eV","volume":"355","author":"Truong","year":"2009","journal-title":"Chem. Phys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1063\/1.444862","article-title":"Dynamical Study of Nonadiabatic Unimolecular Reactions: The Conical Intersection between the B2B2 and A2A1 States of H2O+","volume":"78","author":"Dehareng","year":"1983","journal-title":"J. Chem. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"9893","DOI":"10.1021\/jp103659f","article-title":"Nonadiabatic Nuclear Dynamics after Valence Ionization of H2O","volume":"114","author":"Eroms","year":"2010","journal-title":"J. Phys. Chem. A"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/0020-7381(68)85005-3","article-title":"The Electronic Structures of Methane, Ethane, Ethylene and Formaldehyde Studied by High-Resolution Molecular Photoelectron Spectroscopy","volume":"1","author":"Baker","year":"1968","journal-title":"Int. J. Mass Spectrom. Ion Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/0009-2614(93)85058-V","article-title":"High-Resolution He I\u03b1 Photoelectron Spectroscopy of H2CO and D2CO Using Supersonic Molecular Beams","volume":"201","author":"Niu","year":"1993","journal-title":"Chem. Phys. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4377","DOI":"10.1063\/1.464999","article-title":"High Resolution Photoelectron Spectroscopy and Femtosecond Intramolecular Dynamics of H2CO+ and D2CO+","volume":"98","author":"Niu","year":"1993","journal-title":"J. Chem. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1080\/002689798167494","article-title":"The Electronic Structure of the H2CO+ Radical and Higher Rydberg States of H2CO","volume":"94","author":"Bruna","year":"1998","journal-title":"Mol. Phys."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/S0166-1280(00)00496-6","article-title":"Time-Dependent Density-Functional Theory Investigation of Excitation Spectra of Open-Shell Molecules","volume":"527","author":"Guan","year":"2000","journal-title":"J. Mol. Struct. THEOCHEM"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"052520","DOI":"10.1103\/PhysRevA.89.052520","article-title":"Lifetime of Low Vibrational Levels of the Metastable B 2B2 State of H2O+ Probed by Photodissociation at 532 nm","volume":"89","author":"Harbo","year":"2014","journal-title":"Phys. Rev. A"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"111172","DOI":"10.1016\/j.jms.2019.07.003","article-title":"The Renner-Teller Effect Revisited 40 Years Later","volume":"363","author":"Jungen","year":"2019","journal-title":"J. Mol. Spectrosc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"5222","DOI":"10.1063\/1.464922","article-title":"Theoretical Spin\u2013Rovibronic 2A1(\u03a0u)-2B1 Spectrum of the H2O+, HDO+, and D2O+","volume":"98","author":"Brommer","year":"1993","journal-title":"J. Chem. Phys."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1063\/1.1679310","article-title":"Spectrum of H2O+","volume":"58","author":"Lew","year":"1973","journal-title":"J. Chem. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2028","DOI":"10.1139\/p76-241","article-title":"Electronic Spectrum of H2O+","volume":"54","author":"Lew","year":"1976","journal-title":"Can. J. Phys."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"234308","DOI":"10.1063\/1.5037346","article-title":"A Theoretical Study of the Adiabatic and Vertical Ionization Potentials of Water","volume":"148","author":"Feller","year":"2018","journal-title":"J. Chem. Phys."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4374","DOI":"10.1021\/acs.jctc.1c00307","article-title":"(T)+EOM Quartic Force Fields for Theoretical Vibrational Spectroscopy of Electronically Excited States","volume":"17","author":"Davis","year":"2021","journal-title":"J. Chem. Theory Comput."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/bs.arcc.2019.08.006","article-title":"Computational Vibrational Spectroscopy for the Detection of Molecules in Space","volume":"15","author":"Fortenberry","year":"2019","journal-title":"Ann. Rep. Comput. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1016\/j.saa.2014.07.082","article-title":"Quartic Force Fields for Excited Electronic States: Rovibronic Reference Data for the 1 2A\u2032 and 1 2A\u2032\u2032 States of the Isoformyl Radical, HOC","volume":"135","author":"Morgan","year":"2015","journal-title":"Spectrochim. Acta A"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"7013","DOI":"10.1021\/acs.jpca.5b03489","article-title":"Theoretical Rovibronic Treatment of the X\u02dc2\u03a3+ and 2\u03a0 States of C2H & 1\u03a3+ State of C2H- from Quartic Force Fields","volume":"119","author":"Morgan","year":"2015","journal-title":"J. Phys. Chem. A"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1808","DOI":"10.1063\/1.473322","article-title":"The CC3 Model: An Iterative Coupled Cluster Approach including Connected Triples","volume":"106","author":"Koch","year":"1997","journal-title":"J. Chem. Phys."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"054110","DOI":"10.1063\/1.1835953","article-title":"Coupled Cluster Excited Methods Including Triple Excitations for Excited States of Radicals","volume":"122","author":"Smith","year":"2005","journal-title":"J. Chem. Phys."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"134301","DOI":"10.1063\/1.3643336","article-title":"The trans-HOCO Radical: Fundamental Vibrational Frequencies, Quartic Force Fields, and Spectroscopic constants","volume":"135","author":"Fortenberry","year":"2011","journal-title":"J. Chem. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"8938","DOI":"10.1063\/1.468022","article-title":"Analytic Energy Derivatives for Ionized States Described by the Equation-of-Motion Coupled Cluster Method","volume":"101","author":"Stanton","year":"1994","journal-title":"J. Chem. Phys."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"7029","DOI":"10.1063\/1.464746","article-title":"The Equation of Motion Coupled-Cluster Method\u2014A Systematic Biorthogonal Approach to Molecular Excitation Energies, Transition-Probabilities, and Excited-State Properties","volume":"98","author":"Stanton","year":"1993","journal-title":"J. Chem. Phys."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"221106","DOI":"10.1063\/1.2817618","article-title":"A Simple and Efficient CCSD(T)-F12 Approximation","volume":"127","author":"Adler","year":"2007","journal-title":"J. Chem. Phys."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"084102","DOI":"10.1063\/1.2831537","article-title":"Systematically Convergent Basis Sets for Explicitly Correlated Wavefunctions: The Atoms H, He, B-Ne, and Al-Ar","volume":"128","author":"Peterson","year":"2008","journal-title":"J. Chem. Phys."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"184108","DOI":"10.1063\/1.3009271","article-title":"Optimized Auxiliary Basis Sets for Explicitly Correlated Methods","volume":"129","author":"Yousaf","year":"2008","journal-title":"J. Chem. Phys."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"054104","DOI":"10.1063\/1.3054300","article-title":"Simplified CCSD(T)-F12 Methods: Theory and Benchmarks","volume":"130","author":"Knizia","year":"2009","journal-title":"J. Chem. Phys."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"e25899","DOI":"10.1002\/qua.25899","article-title":"The Performance of CCSD(T)-F12\/aug-cc-pVTZ for the Computation of Anharmonic Fundamental Vibrational Frequencies","volume":"119","author":"Agbaglo","year":"2019","journal-title":"Int. J. Quantum Chem."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"136720","DOI":"10.1016\/j.cplett.2019.136720","article-title":"The Performance of Explicitly Correlated Wavefunctions [CCSD(T)-F12b] in the Computation of Anharmonic Vibrational Frequencies","volume":"734","author":"Agbaglo","year":"2019","journal-title":"Chem. Phys. Lett."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1016\/0009-2614(96)00658-6","article-title":"The Atomization Energy and Proton Affinity of NH3. An AbInitio Calibration Study","volume":"258","author":"Martin","year":"1996","journal-title":"Chem. Phys. Lett."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1016\/0009-2614(94)87114-0","article-title":"Basis Set Convergence for Geometry and Harmonic Frequencies. Are h Functions Enough?","volume":"225","author":"Martin","year":"1994","journal-title":"Chem. Phys. Lett."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/0003-4916(74)90333-9","article-title":"Quantum Electrodynamical Corrections to the Fine Structure of Helium","volume":"82","author":"Douglas","year":"1974","journal-title":"Ann. Phys."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1063\/1.1329891","article-title":"Parallel Douglas-Kroll energy and gradients in NWChem: Estimating scalar relativistic effects using Douglas-Kroll contracted basis sets","volume":"114","author":"Harrison","year":"2001","journal-title":"J. Chem. Phys."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"144107","DOI":"10.1063\/5.0005081","article-title":"The Molpro Quantum Chemistry Package","volume":"152","author":"Werner","year":"2020","journal-title":"J. Chem. Phys."},{"key":"ref_59","unstructured":"Allen, W.D., and Coworkers (2005). INTDER 2005 is a General Program Written by W. D. Allen and Coworkers, which Performs Vibrational Analysis and Higher-Order Non-Linear Transformations."},{"key":"ref_60","unstructured":"Bowman, J.M., and Ratner, M.A. (1991). Advances in Molecular Vibrations and Collision Dynamics, JAI Press, Inc."},{"key":"ref_61","unstructured":"Rao, K.N., and Mathews, C.W. (1972). Molecular Spectroscopy\u2014Modern Research, Academic Press."},{"key":"ref_62","unstructured":"Papousek, D., and Aliev, M.R. (1982). Molecular Vibration-Rotation Spectra, Elsevier."},{"key":"ref_63","unstructured":"During, J.R. (1977). Vibrational Spectra and Structure, Elsevier."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"5853","DOI":"10.1063\/1.467301","article-title":"An Accurate Quartic Force-Field and Vibrational Frequencies for HNO and DNO","volume":"101","author":"Dateo","year":"1994","journal-title":"J. Chem. Phys."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"104301","DOI":"10.1063\/1.3212560","article-title":"Accurate Ab Initio Quartic Force Fields for NH2- and CCH- and Rovibrational Spectroscopic Constants for Their Isotopologs","volume":"131","author":"Huang","year":"2009","journal-title":"J. Chem. Phys."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"2867","DOI":"10.1021\/jp9525447","article-title":"Variational Calculations of Rovibrational Energy Levels and Transition Intensities for Tetratomic Molecules","volume":"100","author":"Schwenke","year":"1996","journal-title":"J. Phys. Chem."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1007\/s002140050379","article-title":"Extensions and Tests of \u201cMultimode\u201d: A Code to Obtain Accurate Vibration\/Rotation Energies of Many-Mode Molecules","volume":"100","author":"Carter","year":"1998","journal-title":"Theor. Chem. Acc."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1080\/00268976.2012.669504","article-title":"Multimode Calculations of Rovibrational Energies of C2H4 and C2D4","volume":"110","author":"Carter","year":"2012","journal-title":"Mol. Phys."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"184102","DOI":"10.1063\/5.0004997","article-title":"NWChem: Past, present, and future","volume":"152","author":"Bylaska","year":"2020","journal-title":"J. Chem. Phys."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"3185","DOI":"10.1021\/acs.jctc.7b00174","article-title":"Psi4 1.1: An Open-Source Electronic Structure Program Emphasizing Automation, Advanced Libraries, and Interoperability","volume":"13","author":"Parrish","year":"2017","journal-title":"J. Chem. Theory Comput."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"8785","DOI":"10.1063\/1.479673","article-title":"A Simple Scheme for the Direct Calculation of Ionization Potentials with Coupled-Cluster Theory That Exploits Established Excitation Energy Methods","volume":"111","author":"Stanton","year":"1999","journal-title":"J. Chem. Phys."},{"key":"ref_72","unstructured":"Stanton, J.F., Gauss, J., Harding, M.E., Szalay, P.G., Auer, A.A., Bartlett, R.J., Benedikt, U., Berger, C., Bernholdt, D.E., and Bomble, Y.J. (2022, October 10). CFOUR. A Quantum Chemical Program Package. Available online: http:\/\/www.cfour.de."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"4572","DOI":"10.1063\/1.470645","article-title":"Gaussian Basis Sets for Use in Correlated Molecular Calculations. V. Core-Valence Basis Sets for Boron through Neon","volume":"103","author":"Woon","year":"1995","journal-title":"J. Chem. Phys."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"020801","DOI":"10.1103\/PhysRevA.102.020801","article-title":"Ab Initio Properties of the NaLi Molecule in the a3\u03a3+ Electronic State","volume":"102","author":"Gronowski","year":"2020","journal-title":"Phys. Rev. A"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"024502","DOI":"10.1103\/PhysRevA.63.024502","article-title":"Estimation of Lamb-Shift Effects for Molecules: Application to the Rotation-Vibration Spectra of Water","volume":"63","author":"Dyall","year":"2001","journal-title":"Phys. Rev. A"},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1002\/qua.560360824","article-title":"A Diagnostic for Determining the Quality of Single-Reference Electron Correlation Methods","volume":"36","author":"Lee","year":"1989","journal-title":"Int. J. Quant. Chem."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"10532","DOI":"10.1021\/acs.jpca.1c08355","article-title":"F12-TZ-cCR: A Methodology for Faster and Still Highly Accurate Quartic Force Fields","volume":"125","author":"Watrous","year":"2021","journal-title":"J. Phys. Chem. A"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"3191","DOI":"10.1021\/acs.jpca.0c01609","article-title":"Anharmonic Frequencies of (MO)2 and Related Hydrides for M = Mg, Al, Si, P, S, Ca, and Ti and Heuristics for Predicting Anharmonic Corrections of Inorganic Oxides","volume":"124","author":"Westbrook","year":"2020","journal-title":"J. Phys. Chem. A"},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0022-2852(88)90003-3","article-title":"Infrared Spectroscopy of the \u03bd3 Band of H2O+","volume":"127","author":"Dinelli","year":"1988","journal-title":"J. Mol. Spectrosc."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"5977","DOI":"10.1063\/1.463735","article-title":"Infrared Spectroscopy and Equilibrium Structure of H2O+ (X 2B1)","volume":"97","author":"Huet","year":"1992","journal-title":"J. Chem. Phys."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"7033","DOI":"10.1063\/1.461431","article-title":"Rotationally Resolved Photoionization of H2O+","volume":"95","author":"Tonkyn","year":"1991","journal-title":"J. Chem. Phys."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"3384","DOI":"10.1063\/1.456913","article-title":"Infrared Laser Spectroscopy of the 201 and 212 Bands of H2O+ (X2B1)","volume":"91","author":"Brown","year":"1989","journal-title":"J. Chem. Phys."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"A128","DOI":"10.1051\/0004-6361\/201629073","article-title":"OH+ and H2O+ Absorption toward PKS 1830\u2013211","volume":"595","author":"Muller","year":"2016","journal-title":"Astron. Astrophys."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"9797","DOI":"10.1063\/1.1370943","article-title":"Multiphoton Ionization and Photoelectron Spectroscopy of Formaldehyde via its 3p Rydberg States","volume":"114","author":"Liu","year":"2001","journal-title":"J. Chem. Phys."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.jms.2008.04.005","article-title":"The Formaldehyde Cation: Rovibrational Energy Level Structure and Coriolis Interaction Near the Adiabatic Ionization Threshold","volume":"250","author":"Schulenburg","year":"2008","journal-title":"J. Mol. Spectrosc."},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"244303","DOI":"10.1063\/1.5125268","article-title":"Spectroscopic Investigation of [Al,N,C,O] Refractory Molecules","volume":"151","author":"Trabelsi","year":"2019","journal-title":"J. Chem. Phys."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1063\/1.432251","article-title":"A Many-Body Approach to the Vibrational Structure in Molecular Electronic Spectra. II. Application to Nitrogen, Carbon Monoxide, and Formaldehyde","volume":"64","author":"Domcke","year":"1976","journal-title":"J. Chem. Phys."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/4\/1782\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:34:12Z","timestamp":1760121252000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/4\/1782"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,13]]},"references-count":87,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["molecules28041782"],"URL":"https:\/\/doi.org\/10.3390\/molecules28041782","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,2,13]]}}}