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Trimers formed by formaldehyde with hydrogen fluoride: Structures, energetics, and infrared absorption spectra. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Neogi SG, Alam MM. Structure, Carbonyl Vibrational Frequencies, and Local Energy Decomposition of Binding Energy in Formaldehyde Clusters, (HCHO) n=1-10. J Phys Chem A 2022; 126:416-423. [PMID: 35025494 DOI: 10.1021/acs.jpca.1c08789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work, structures, vibrational frequencies, and binding energies of formaldehyde clusters, (HCHO)n=1-10, are investigated by using global optimization genetic algorithm followed by density functional theory calculations and local energy decomposition (LED) analysis at the high-end DLPNO-CCSD(T) level of theory. With the use of genetic algorithm, different structures of all clusters are generated, which are further refined by the quantum chemical geometry optimization technique. From those structures, the conformer with the lowest energy is chosen and used for further analysis. The variation in carbonyl stretching frequency with change in cluster size is discussed and compared with available experimental data. Furthermore, by using standard and advanced LED analysis, different components of the binding energy are studied in all clusters and their variations with cluster size are also discussed.
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Affiliation(s)
- Soumya Ganguly Neogi
- Department of Chemistry, Chandernagore College, Hooghly, West Bengal 712136, India
| | - Md Mehboob Alam
- Department of Chemistry, Indian Institute of Technology Bhilai, Raipur, Chhattisgarh 492015, India
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Abstract
In this work, a computational study on the ionization potentials (IPs) of the formaldehyde trimer, (H2CO)3, is presented. Twelve lowest-lying vertical IPs were determined through the use of the coupled-cluster level of theory using correlation consistent basis sets with extrapolation to the complete basis set limit and consideration of core electron correlation effects. Specifically, the equation-of-motion ionization potential coupled-cluster with single and double excitations method with the aug-cc-pVnZ and aug-cc-pCVnZ (n = D and T) basis sets was used. The Feller-Peterson-Dixon (FPD) composite approach was employed to provide accurate IPs, and eight conformations of (H2CO)3 were considered. The FPD IPs determined for (H2CO)3 were found to be systematically lower than those computed for the dimer and monomer of H2CO in the pattern IP(monomer) > IP(dimer) > IP(trimer) for a given IP. In addition, the IPs calculated when considering only the more stable conformation (C0) are in good agreement with those obtained using the eight conformations of the H2CO trimer, and thus, the actual conformation played only a minor role in determining such properties in the present case. By providing first accurate IP results for the H2CO trimer, we hope to motivate future experimental and computational investigations (e.g., studies involving photoionization) that rely on such quantities.
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Affiliation(s)
- Gabriel L C de Souza
- Departamento de Química, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
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Ohno K, Kishimoto N, Iwamoto T, Satoh H, Watanabe H. High performance global exploration of isomers and isomerization channels on quantum chemical potential energy surface of H 5 C 2 NO 2. J Comput Chem 2021; 42:192-204. [PMID: 33146910 DOI: 10.1002/jcc.26446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 11/07/2022]
Abstract
High performance global exploration of isomers and isomerization channels on the quantum chemical potential energy surface (PES) is performed for H5 C2 NO2 by using the scaled hypersphere search-anharmonic downward distortion following (SHS-ADDF) method. A multi-node operation, NeoGRRM, has achieved high performance exploration calculations for the large system by submitting SHS-ADDF sub-jobs into many cores in parallel and unifying the results of sub-jobs into the total lists of the main-job. Global exploration of equilibrium (EQ) and transition-state structures at the level of B3LYP/6-31G(d) gave 3210 EQs and 23278 TSs. Nine compounds were found in the low energy regions of 0-100 kJ/mol; the lowest energy compound is N-methylcarbamic acid, the second is methyl carbamate, and the third is glycine (the most fundamental amino acid). Interconversion pathways between the conformers of each of the low energy compounds were surveyed. Isomerization channels around glycine were explored in detail. The lowest energy barriers around some of the EQs turned to be negative after zero-point energy corrections. This indicates that those structures cannot exist as independent structures because they spontaneously collapse into more stable structures. The global PES search showed various interesting dissociating channels which indicate synthon reaction pathways in the reverse directions.
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Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Naoki Kishimoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Takeaki Iwamoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Hiroko Satoh
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, University of Zurich, Zurich, Switzerland.,Research Organization of Information and Systems (ROIS), Tokyo, Japan
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de Souza GLC, Peterson KA. Probing the ionization potentials of the formaldehyde dimer. J Chem Phys 2020; 152:194305. [PMID: 33687222 DOI: 10.1063/5.0009658] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In this work, we present a computational investigation on the ionization potentials (IPs) of the formaldehyde dimer, (H2CO)2. Twelve lowest lying IPs (corresponding to the entire valence orbitals) for both C2h and Cs symmetry conformers have been computed at the coupled cluster level of theory using large correlation consistent basis sets with extrapolation to the complete basis set limit and consideration of core electron correlation effects. Specifically, the equation-of-motion ionization potential coupled-cluster with single and double (EOMIP-CCSD) excitations method with the aug-cc-pVXZ and aug-cc-pCVXZ (X = T, Q, and 5) basis sets combined with the Feller-Peterson-Dixon approach was employed, as well as CCSD with perturbative triples [CCSD(T)] with the aug-cc-pVTZ basis sets. In general, excellent agreement was observed from the comparison between the results obtained through the use of these approaches. In addition, the IPs for the formaldehyde monomer were also obtained using such methodologies and the results compared with existing experimental data; excellent agreement was also observed in this case. To the best of our knowledge, this work represents the first of its kind to determine the IPs for all these systems using a high level theory approach and is presented to motivate experimental investigations, e.g., studies involving photoionization, particularly for the formaldehyde dimer. The equilibrium binding energy of the C2h dimer is calculated in this work at the CCSD(T)/aug-cc-pVTZ level of theory to be -4.71 kcal/mol. At this same level of theory, the equilibrium isomerization energy between C2h and Cs conformers is 0.76 kcal/mol (Cs conformer being more stable).
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Affiliation(s)
- Gabriel L C de Souza
- Departamento de Química, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
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Quantum chemical exploration of polymerized forms of polycyclic aromatic hydrocarbons: D6h tetramer and polymer of coronene. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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A computational study on multiple formaldehyde complexes and their possible chemical reactions as well as the catalytic effect in the gas phase. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2443-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Ohno K, Oki T, Yamakado H. Quantum Chemical Exploration of Intermolecular Reactions of Acetylene. J Comput Chem 2020; 41:687-697. [PMID: 31793029 DOI: 10.1002/jcc.26120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/12/2019] [Accepted: 11/12/2019] [Indexed: 11/09/2022]
Abstract
Quantum chemical explorations of potential energy surfaces showed that acetylene produces various products starting from molecular arrays in short distances of 1.3-2.5 Å. Arrays of (C2 H2 )2 gave cyclobutadiene, tetrahedrane, and acetylene dimers. Arrays of (C2 H2 )3 gave benzene, prismane, benzvalene, Dewar benzene, and acetylene trimers. Arrays of (C2 H2 )4 gave cubane, cyclooctatetranene, and acetylene tetramers. Different forms of initial arrays yielded different sets of products; a parallel array of two monomers gave cyclobutadiene, whereas a cross array gave tetrahedrane. Initial molecular arrays with unusually close contacts were estimated to require local forces of 1-9 × 10-8 N. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Konan 1-9-36, Minato-ku, Tokyo, 108-0075, Japan.,Tohoku University, Graduate School of Science, Aramaki Aza-Aoba 6-3, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Takuto Oki
- Faculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama, Wakayama, 640-8510, Japan
| | - Hideo Yamakado
- Faculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama, Wakayama, 640-8510, Japan
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Ohno K, Satoh H, Iwamoto T. Quantum chemical exploration of new π-electron systems: Capsule-formed dimers of polycyclic aromatic hydrocarbons. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.04.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ohno K, Satoh H, Iwamoto T. Quantum chemical exploration of dimeric forms of polycyclic aromatic hydrocarbons, naphthalene, perylene, and coronene. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2018.12.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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