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Journal articles on the topic 'Hartree-Fock and DFT Studies'

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Published: 3 June 2025

Last updated: 31 July 2025

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1

Neville, J. J., Y. Zheng, B. P. Hollebone, et al. "EMS studies of larger molecules of chemical and biochemical interest." Canadian Journal of Physics 74, no. 11-12 (1996): 773–81. http://dx.doi.org/10.1139/p96-111.

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The challenges involved in extending electron momentum spectroscopy (EMS) studies beyond small polyatomic molecules to more complicated systems are discussed. EMS results for the highest occupied (frontier) molecular orbitals of glycine (NH2CH2COOH) and dimethoxymethane ((CH3O)2CH2) demonstrate possible approaches to overcoming such challenges as closely spaced valence orbitals, low volatility, and the conformational mobility of the target compound. The increased sensitivity available from recently developed multichannel electron momentum spectrometers is a key factor in overcoming these chall

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2

Maley, S. M., and R. C. Mawhinney. "How the Amount of Hartree-Fock Exchange Affects the Observation of the Pseudo Jahn-Teller Effect." Journal of Physics: Conference Series 2769, no. 1 (2024): 012003. http://dx.doi.org/10.1088/1742-6596/2769/1/012003.

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Abstract Heavy group 14 analogs of planar carbon molecules are well known to prefer bent or pyramidalized geometries. The pseudo Jahn-Teller effect (pJTE) is a general approach to understanding the origin of such molecular geometries. Computationally intensive multi-reference post Hartree-Fock methods are generally required to obtain values relevant to the pJTE. However, an alternative approach, using more computationally efficient density functional theory (DFT) and fitting a model vibronic Hamiltonian, can account for the pJTE parameters. Previous studies have detailed the effect of both int

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3

K h u d a y k u l o v, B., A. A b s a n o v, U. H o l i k u l o v, and B. I l t a z a r o v. "STUDY OF FORMAMIDE - WATER COMPLEXES WITH RAMAN SPECTROSCOPY AND THEORETICAL CALCULATIONS." 2022-yil, 3-son (133/1) ANIQ FANLAR SERIYASI 5, no. 129/2 (2021): 1–10. http://dx.doi.org/10.59251/2181-1296.v5.1292.878.

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: In this work, the geometric optimization of molecular complexes in aqueous solutions of an isolated formamide molecule in three different methods: Hartree-Fock (HF), density function theory (DFT) and the second order Møller–Plesset (MP2) pertrubation theory studied on the set of bases 6-311++G (2d, p).

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Mohandass, P., S. Perumal, S. T. R. Dhanasekaran, P. Padmavathi, and K. K. Mothilal. "Spectroscopic Investigations, Computational Studies and Molecular Properties of Naphthalene Derivatives." Shanlax International Journal of Arts, Science and Humanities 9, S1-May (2022): 47–69. http://dx.doi.org/10.34293/sijash.v9is1-may.5944.

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Theoretical studies have been carried out on bio active molecules such as Naphthalene (npa) and its derivatives naphthalene-2-sulfonic acid (nsa) and 1-nitroso-2-naphthol (nnol) using both Ab initio HF and DFT-B3LYP methods with 6-311++G(d,2p) basis sets. The geometrical parameters, molecular properties and vibrational spectra of nsa, nnol and npa were calculated and analyzed. Geometrical optimizations of the nsa, nnol and npa molecules were done by Density Functional Theory (DFT) using the B3LYP function and Hartree-Fock (HF) level with 6-311++G(d,2p) basis set. The optimized molecular geomet

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Zavodnik, Valery, Adam Stash, Vladimir Tsirelson, Roelof de Vries, and Dirk Feil. "Electron density study of urea using TDS-corrected X-ray diffraction data: quantitative comparison of experimental and theoretical results." Acta Crystallographica Section B Structural Science 55, no. 1 (1999): 45–54. http://dx.doi.org/10.1107/s0108768198005746.

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The electron-density distribution in urea, CO(NH2)2, was studied by high-precision single-crystal X-ray diffraction analysis at 148 (1) K. An experimental correction for TDS was applied to the X-ray intensities. R merge(F 2) = 0.015. The displacement parameters agree quite well with results from neutron diffraction. The deformation density was obtained by refinement of 145 unique low-order reflections with the Hansen & Coppens [Acta Cryst. (1978), A34, 909–921] multipole model, resulting in R = 0.008, wR = 0.011 and S = 1.09. Orbital calculations were carried out applying different potenti

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6

Thangarasu, S., V. Siva, A. Shameem, A. Murugan, S. Athimoolam, and S. Asath Bahadur. "Structural, Electronic, Molecular Orbital Analysis and Charge Distributions on Nitrate Salt of Guanidine through DFT and TD-DFT Methods." Asian Journal of Chemistry 33, no. 8 (2021): 1905–10. http://dx.doi.org/10.14233/ajchem.2021.23201.

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Guanidinium nitrate, a non-linear optical material has been systematically studied through quantum chemical (density functional theory and Hartree Fock) methods. Studies on Mulliken charge, Frontier molecular orbitals (FMOs) and hyperpolarizability analyses have been performed. The Mulliken population analyses were carried out for the optimized molecular geometry by HF and B3LYP methods with 6-311++G(d,p) levels. The molecular orbital parameters of guanidinium nitrate have been calculated by FMO analysis. Frontier molecular orbital (FMO) analysis indicates the electron delocalization on the gu

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7

Kumar, Vibha, Seema Baniwal, and Deepa Saini. "COMPUTATIONAL STUDIES ON CAGE/NON-CAGE STRUCTURES OF OCTACARBORANE DIANION SERIES." Annals of Science and Allied Research 2, no. 1 (2024): 1–9. https://doi.org/10.5281/zenodo.12596721.

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Only cage structures of octacarborane have been reported in the literature, some stable non-cage structures for the same have been found for the first time in this work. A complete isoelectronic dianion series of carboranes of B<sub>8</sub>H<sub>8</sub><sup>2</sup>- have been investigated, each time a B-H unit being replaced by a bare carbon hence forming a dianion series of general formula C<sub>n</sub>B<sub>8-n</sub>H<sub>8-n</sub><sup>2-</sup> (n=1-8). The work has been carried out using Gaussian98 software at Hartree-Fock and DFT levels using 6-31G basis sets both with and without polariza

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8

Kanakaraju, R., and P. Kolandaivel. "Post Hartree–Fock and DFT Studies on Pyrrole···Nitrogen and Pyrrole···Carbon Monoxide Molecules." International Journal of Molecular Sciences 3, no. 7 (2002): 777–89. http://dx.doi.org/10.3390/i3070777.

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9

Amara, Sarah, Noureddine Tchouar, and Salah Belaidi. "Computational Study of some Double Headed Acyclo-C-Nucleosides." International Letters of Chemistry, Physics and Astronomy 61 (November 2015): 1–11. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.61.1.

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In the present paper we have a focus in a study of theoretical characterization of three double headed acyclo-C-nucleosides, which are a recent target of experimental studies. The structural and electronic properties of double headed acyclo-C-nucleosides, 1,4-bis (3-mercapto-1H-1,2,4-triazol-5-yl) butane-1,2,3,4-tetrol, 1,4-bis (4-amino-5-mercapto-4H-1,2,4-triazol-3-yl) butane-1,2,3,4-tetrol and 5,5'-(1,2,3,4-tetrahydroxybutane-1,4-diyl) bis (1,3,4-oxadiazole-2(3H)-thione), have been investigated theoretically by performing semi-empirical molecular orbital, ab initio Hartree-Fock (HF) and Dens

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Amara, Sarah, Noureddine Tchouar, and Salah Belaidi. "Computational Study of some Double Headed Acyclo-C-Nucleosides." International Letters of Chemistry, Physics and Astronomy 61 (November 3, 2015): 1–11. http://dx.doi.org/10.56431/p-old94x.

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In the present paper we have a focus in a study of theoretical characterization of three double headed acyclo-C-nucleosides, which are a recent target of experimental studies. The structural and electronic properties of double headed acyclo-C-nucleosides, 1,4-bis (3-mercapto-1H-1,2,4-triazol-5-yl) butane-1,2,3,4-tetrol, 1,4-bis (4-amino-5-mercapto-4H-1,2,4-triazol-3-yl) butane-1,2,3,4-tetrol and 5,5'-(1,2,3,4-tetrahydroxybutane-1,4-diyl) bis (1,3,4-oxadiazole-2(3H)-thione), have been investigated theoretically by performing semi-empirical molecular orbital, ab initio Hartree-Fock (HF) and Dens

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Priyanka, Sanjay Kumar Srivastava, and Diksha Katiyar. "Combined experimental and theoretical studies on 4-(2-hydroxy-3-morpholin-4-yl-propoxy)-chromen-2-one." Journal of Theoretical and Computational Chemistry 15, no. 02 (2016): 1650017. http://dx.doi.org/10.1142/s0219633616500176.

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The FTIR, UV–Vis and NMR spectra of 4-(2-hydroxy-3-morpholin-4-yl-propoxy)-chromen-2-one (4-HMPC) have been recorded and analyzed. The optimized geometry and harmonic vibrational frequencies of 4-HMPC were obtained by the Hartree–Fock (HF) and density functional theory (DFT) using B3LYP functional with 6-311[Formula: see text]G basis set. The 1H and [Formula: see text]C NMR chemical shifts were calculated by the GIAO method in chloroform. The absorption spectra of 4-HMPC were computed in ethanol and water solutions using TD-B3LYP/6-311[Formula: see text]G(d,p) approach. The correlation of theo

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12

Thangarasu, Subramanian, Vadivel Siva, Shunmuganarayanan Athimoolam, and Sultan Asath Bahadur. "Synthesis, Spectroscopic Studies, Antimicrobial Activity and Computational Calculations on 3-Nitroanilinium Dihydrogen Phosphate." Asian Journal of Chemistry 33, no. 5 (2021): 1099–106. http://dx.doi.org/10.14233/ajchem.2021.23086.

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3-Nitroanilinium dihydrogen phosphate (3NADP) has been synthesized and crystallized successfully using the method of solvent evaporation solution growth. The molecular structure has been optimized and geometrical parameters of 3NADP also have been analyzed using B3LYP function with density functional theory (DFT) and Hartree-Fock (HF) methods with a 6-311++G(d,p) basis set. The comparison between computed vibrational spectra and experimental result shows an appreciable agreement. The thermal stability of 3NADP crystal was analyzed using TG/DTA and the melting point was identified at 209 ºC. Th

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13

Thangarasu, S., V. Siva, S. Asath Bahadur, and S. Athimoolam. "Structural, Vibrational, Quantum Chemical Calculations, Thermal and Antimicrobial Studies on Sulphate Salt of 3-Nitroaniline." Asian Journal of Chemistry 33, no. 1 (2020): 231–39. http://dx.doi.org/10.14233/ajchem.2021.22966.

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In this work, bis(3-nitroanilinium) sulfate (3NASU) has been synthesized and crystallized successfully by solution growth combined with solvent evaporation technique. The studied salt, 3NASU molecular structure has been optimized with density functional theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311++G(d,p) basis set. The geometrical parameters of 3NASU have been analyzed. The computed vibrational spectra were compared with experimental result which show appreciable agreement. Thermal stability of the crystal was analyzed with TGA/DTA and the melting points of the salt

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14

Pal, Snehanshu, and T. K. Kundu. "Stability Analysis and Frontier Orbital Study of Different Glycol and Water Complex." ISRN Physical Chemistry 2013 (January 13, 2013): 1–16. http://dx.doi.org/10.1155/2013/753139.

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A detailed theoretical study of hydrogen-bond formation in different polyethylene glycol + water complex and dipropylene glycol + water have been performed by Hartree Fock (HF) method, second-order Møller-Plesset perturbation theory (MP2), and density functional theory (DFT) using 6-31++G(d,p) basis set. B3LYP DFT-D, WB97XD, M06, and M06-2X functionals have been used to describe highly dispersive hydrogen-bond formation appropriately. Geometrical parameters, interaction energies, deformation energies, deviation of potential energy curves of hydrogen bonded O–H from that of free O–H, frontier o

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15

Prasanti, Marla, Anjali Jha, and Ch Ravi Shankar Kumar. "Electronic Properties of Aldehyde Complexes Using DFT for Electrooptical Activity." Materials Science Forum 1048 (January 4, 2022): 212–20. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.212.

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Characterization of materials infer for physical and chemical properties that depend on its molecular structure. Structure of molecule has its dependence on respective electrons of molecule under consideration occupying their positions that correspond to changes in density of electrons. Many theories of its kind were developed to study density of electrons with roots from wavefunction method and electron density method. Wavefunction method has its dependence with linear combination of atomic orbitals, Born approximation, variational principle ,potential energy surfaces for development of Hucke

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16

Aydogdu, Immihan Sezen, Ilkay Gumus, and Hakan Arslan. "Hirshfeld surface and theoretical studies of 2,2,2-trichloro-N,N-bis(2-(2,2,2-trichloroacetamido)phenyl)acetamide compound." European Journal of Chemistry 10, no. 4 (2019): 323–35. http://dx.doi.org/10.5155/eurjchem.10.4.323-335.1920.

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The vibrational frequencies, atomic charges and the related properties of the 2,2,2-trichloro-N,N-bis(2-(2,2,2-trichloroacetamido)phenyl)acetamide (H2LNNN) were investi-gated by Ab-initio Hartree-Fock (HF) and Density Functional Theory (DFT) methods such as BLYP, B3LYP, B3PW91 and mPW1PW91 functionals with 6-31G(d,p) and 6-311G(d,p) basis sets. The experimentally determined parameters were compared with those calculated theoretically and they were found to complement each other with a very good correlation. The theoretical vibrational spectrum of H2LNNN molecule was interpreted by means of pot

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Lobato, Cleison C., Rai C. Silva, Vitor H. S. Sanches та ін. "Application of Chemometric Techniques for Validation of Computational Methods Applied in Molecular Modeling of 6α-Hidroxyvouacapan-7β, 17β-Lactone with Antiproliferative Activity in Leukemia Cells". Journal of Computational and Theoretical Nanoscience 17, № 11 (2020): 4855–65. http://dx.doi.org/10.1166/jctn.2020.9461.

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Hidroxyvouacapan-6α-7β, 17β-lactone (HVL) is a synthetic derivative of 6α, 7β-dihydroxyvouacapan-17β-oic acid (ADV) which was isolated from the fruits of Pterodon polygalaeflorus Benth. Both compounds showed anti-inflammatory and analgesic activities. According to studies conducted by Euzébio et al. in 2009 and 2010, ADV, HVL and some derivatives showed antiproliferative activity in different line of cancer cells, including the K562 leukemia. In this paper, we propose a combination of quantum-chemical methods, multivariate analysis and statistical to assess semi-empirical (AM1, PM3 and ZINDO),

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18

Al-Wahaibi, Lamya H., Munusamy Govindarajan, Ali A. El-Emam, and Mohamed I. Attia. "Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR) insights, electronic profiling and DFT computations on ({(E)-[3-(1H-imidazol-1-yl)-1-phenylpropylidene] amino}oxy)(4-nitrophenyl)methanone, an imidazole-bearing anti-Candida agent." Open Chemistry 16, no. 1 (2018): 50–63. http://dx.doi.org/10.1515/chem-2018-0005.

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AbstractThe anti-Candida agent, ({(E)-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]amnio}oxy(4-nitropheny) methanone (IPAONM), was subjected to comprehensive spectroscopic (FT-IR, FT-Raman, UV–Vis 1H and 13C NMR) characterization as well as Hartree Fock and density functional theory computation studies. The selected optimized geometric bond lengths and bond angles of the IPAONM molecule were compared with the experimental values. The calculated wavenumbers have been scaled and compared with the experimental spectra. Mulliken charges and natural bond orbital analysis of the title molecule were cal

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Zhao, Dongbo, Shubin Liu, and Dahua Chen. "A Density Functional Theory and Information-Theoretic Approach Study of Interaction Energy and Polarizability for Base Pairs and Peptides." Pharmaceuticals 15, no. 8 (2022): 938. http://dx.doi.org/10.3390/ph15080938.

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Using density functional theory (DFT) and the information-theoretic approach (ITA) quantities to appreciate the energetics and properties of biopolymers is still an unaccomplished and ongoing task. To this end, we studied the building blocks of nucleic acid base pairs and small peptides. For base pairs, we have dissected the relative importance of energetic components by using two energy partition schemes in DFT. Our results convincingly show that the exchange-correlation effect predominantly governs the molecular stability of base pairs while the electrostatic potential plays a minor but indi

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Chandran, Asha, Sheena Mary, Hema Tresa Varghese, et al. "Vibrational Spectroscopic Study of (E)-4-(Benzylideneamino)-N-Carbamimidoyl Benzenesulfonamide." ISRN Analytical Chemistry 2012 (January 19, 2012): 1–11. http://dx.doi.org/10.5402/2012/397026.

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The Fourier transform infrared and Fourier transform Raman spectra of (E)-4-(benzylideneamino)-N-carbamimidoyl benzenesulfonamide were recorded and analyzed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian 03 set of quantum chemistry codes. Calculations were performed at the Hartree-Fock (HF) and density functional theory (DFT; B3PW91, B3LYP) levels of theory. The calculated wavenumbers (B3LYP) agree well with the observed wavenumbers. Potential energy distribution is done using GAR2PED program. The red shift of the N-H stretching band in the infrared

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Almásy, László, and Attila Bende. "Intermolecular Interaction in Methylene Halide (CH2F2, CH2Cl2, CH2Br2 and CH2I2) Dimers." Molecules 24, no. 9 (2019): 1810. http://dx.doi.org/10.3390/molecules24091810.

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The intermolecular interaction in difluoromethane, dichloromethane, dibromomethane, and diiodomethane dimers has been investigated using high level quantum chemical methods. The potential energy curve of intermolecular interaction along the C⋯C bond distance obtained using the coupled-cluster theory with singles, doubles, and perturbative triples excitations CCSD(T) were compared with values given by the same method, but applying the local (LCCSD(T)) and the explicitly correlated (CCSD(T)-F12) approximations. The accuracy of other theoretical methods—Hartree–Fock (HF), second order Møller–Ples

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Martínez, Joel, Maricarmen Hernández-Rodríguez, Abraham Méndez-Albores, et al. "Computational Studies of Aflatoxin B1 (AFB1): A Review." Toxins 15, no. 2 (2023): 135. http://dx.doi.org/10.3390/toxins15020135.

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Aflatoxin B1 (AFB1) exhibits the most potent mutagenic and carcinogenic activity among aflatoxins. For this reason, AFB1 is recognized as a human group 1 carcinogen by the International Agency of Research on Cancer. Consequently, it is essential to determine its properties and behavior in different chemical systems. The chemical properties of AFB1 can be explored using computational chemistry, which has been employed complementarily to experimental investigations. The present review includes in silico studies (semiempirical, Hartree–Fock, DFT, molecular docking, and molecular dynamics) conduct

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Jankowski, Karol, Ireneusz Grabowski, Krzysztof Nowakowski, and Jan Wasilewski. "Ab initio Correlation Effects in Density Functional Theories: An Electron-Distribution-Based Study for Neon." Collection of Czechoslovak Chemical Communications 70, no. 8 (2005): 1157–76. http://dx.doi.org/10.1135/cccc20051157.

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We have briefly reviewed the idea of studies aiming at such a bridging of the methodological gap between ab initio methods (or wave function theory (WFT)) and density functional theory (DFT) that would afford carrying over results concerning details of the structure of correlation effects from one method to the other. Special attention is paid to the problem of coverage of the WFT correlation effects by the exchange-correlation functionals of DFT. A short survey of the concept of supplementing energy-based investigations in this field by electron-density-based studies is given and illustrated

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Das, Birinchi K., Sanchay J. Bora, Manjit K. Bhattacharyya, and Rama K. Barman. "Inverse bilayer structure of mononuclear CoII and NiII complexes of the type M(H2O)3(SO4)(4-CNpy)2." Acta Crystallographica Section B Structural Science 65, no. 4 (2009): 467–73. http://dx.doi.org/10.1107/s0108768109021090.

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Two new metal compounds of the formula [M(H2O)3(SO4)(4-CNpy)2]·H2O [M = Ni (1) and Co (2), 4-CNpy = 4-cyanopyridine] have been prepared and studied by X-ray diffraction. In both of these compounds the 4-CNpy ligands are coordinated via pyridyl-N atoms to the metal ions in a cis fashion. The neutral complexes along with the uncoordinated H2O molecules are glued together preferentially into inverse bilayers by non-covalent interactions, including unique interlayer π–π interactions between antiparallel nitrile groups. Hartree–Fock and density-functional theory (DFT) calculations indicate that the

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Sagdinc, Seda, Yesim Kara, and Filiz Kayadibi. "Theoretical study of 11-thiocyanatoundecanoic acid phenylamide derivatives on corrosion inhibition efficiencies." Canadian Journal of Chemistry 92, no. 9 (2014): 876–87. http://dx.doi.org/10.1139/cjc-2014-0076.

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Ab initio Hartree–Fock (HF) and Density Functional Theory (DFT) B3LYP methods with the 6-311G(d,p) basis set were applied to the three 11-thiocyanatoundecanoic acid phenylamide derivatives as corrosion inhibitors. Inhibition efficiency obtained experimentally followed the following order: N-(4-methoxyphenyl)-11-thiocyanatoundecanamide (N3MPTUA) > N-phenyl-11-thiocyanatoundecanamide (NPTUA) > N-(3-nitrophenyl)-11-thiocyanatoundecanamide (N3NPTUA). The molecular parameters most relevant to their potential action as corrosion inhibitors have been calculated in the neutral and protonated for

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Hobza, Pavel, and Zdeněk Havlas. "Counterpoise-Corrected Potential Energy Surfaces of Simple Hydrogen-Bonded Systems." Collection of Czechoslovak Chemical Communications 63, no. 9 (1998): 1343–54. http://dx.doi.org/10.1135/cccc19981343.

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Geometric and energetic characteristics of various simple hydrogen-bonded complexes (water dimer, hydrogen fluoride dimer, formamide dimer, formic acid dimer, glycine dimer) have been studied by gradient optimization, which a priori eliminates the basis set superposition error (BSSE) by using the counterpoise (CP) method, as well as by the standard gradient optimization. Calculations were done at the Hartree-Fock, correlated MP2 and DFT levels with small- and medium-basis sets. The CP-corrected and standard PESs differ, depending on the theoretical level used. Larger differences were found if

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MBOUOMBOUO, Ibrahim NDASSA, Gouet Bebga, Martin Signé, François Volatron, and Bernard Silvi. "THEORETICAL STUDY OF CHLORINATION REACTION OF NITROBENZENE FROM DFT CALCULATIONS." JOURNAL OF ADVANCES IN CHEMISTRY 11, no. 9 (2015): 3784–93. http://dx.doi.org/10.24297/jac.v11i9.2690.

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The geometric parameters of stationary points on the potential surface energy of the chlorination reaction of nitrobenzene in the presence of Aluminium chloride as catalyst were investigated theoretically by hybrid DFT (Density Functional Theory) calculations in order to determine his general reaction mechanism in gas phase and in solution. The results obtained by DFT have been compared with CCSD(T) method which is the most powerful post-Hartree Fock method in terms of inclusion of dynamic correlation. Although the electrophilic substitution reaction is widely taught in most courses in organic

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Ghafoor, Sidra, Asim Mansha, Sadia Asim, Muhammad Usman, Ameer Fawad Zahoor, and Hafiz Saqib Ali. "The structural, spectral, frontier molecular orbital and thermodynamic analysis of 2-hydroxy 2-methyl propiophenone by MP2 and B3LYP methods." Journal of Theoretical and Computational Chemistry 19, no. 05 (2020): 2050020. http://dx.doi.org/10.1142/s0219633620500200.

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In the present work, we have studied the 2-hydroxy 2-methyl propiophenone (2H2MPP) theoretically as well as experimentally. The optimized molecular structure has been obtained by the density functional theory (DFT), second-order Moller–Plesset perturbation theory (MP2) and Hartree Fock (HF) in the gas phase as well as in different media like ethanol, DMSO and heptane. FT-IR and FT-Raman spectra were computed as well as recorded and fundamental vibrational wavenumbers were assigned. The electronic absorption spectra were calculated by employing the time-dependent density functional theory (TD-D

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Kumari, Neha, Ruchika Sharma, Archana Akaram Yadav, et al. "Synthesis, crystal structure, DFT/HF, Hirshfeld surface, and molecular docking analysis of 4-(tert-butyl)-4-nitro-1,1-biphenyl." European Journal of Chemistry 14, no. 1 (2023): 90–98. http://dx.doi.org/10.5155/eurjchem.14.1.90-98.2386.

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4-(tert-Butyl)-4-nitro-1,1-biphenyl has been synthesized, and its structure has been characterized by using some spectroscopic and single-crystal X-ray diffraction techniques. It crystallizes in a monoclinic crystal system with space group P21/n and unit cell parameters: a = 6.4478(3) Å, b = 9.2477(4) Å, c = 23.4572(9) Å, β = 95.114(4)°, V = 1393.11(10) Å3, Z = 4. The molecular structure has been solved by using the intrinsic phasing method. The crystal structure is stabilized by C-H···O interactions. Computational studies were performed using density functional theory (DFT) and Hartree-Fock (

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Thangarasu, S., V. Siva, S. Athimoolam, and S. Asath Bahadur. "Molecular structure, spectroscopic and quantum chemical studies on benzoic acid and succinic acid co-crystals of 2-aminopyrimidine." Journal of Theoretical and Computational Chemistry 17, no. 04 (2018): 1850021. http://dx.doi.org/10.1142/s0219633618500219.

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Organic nonlinear optical co-crystals 2-aminopyrimidine benzoic acid (2APB) and 2-aminopyrimidine succinic acid (2APS) have been successfully grown by slow solvent evaporation method at room temperature. The structural characterization of the grown crystals was carried out by single crystal X-ray diffraction. Fourier transform infrared spectroscopy (FT-IR) and FT-Raman spectra of the grown crystals are recorded and the observed vibrational frequencies are assigned. The hybrid computational calculations are carried out by Hartree–Fock (HF) and density functional theory (DFT) (3-parameter, Lee-Y

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Belciya, J. Jebamalar, R. Anitha, M. Mohamed Roshan, R. Renugadevi, and S. Athimoolam. "Synthesis, Quantum Chemical, Spectral, Optical, Thermal and Biological Studies on Sulfamethazine Single Crystal." Asian Journal of Chemistry 37, no. 6 (2025): 1358–66. https://doi.org/10.14233/ajchem.2025.33773.

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The single crystal of the pharmaceutical drug sulfamethazine has been grown using the slow evaporation method at ambient temperature. The analysis of the single crystal X-ray diffraction (XRD) data indicates that the grown crystal belongs to the monoclinic crystal system. This classification is based on the symmetry and the lattice parameters observed during the single crystal XRD analysis. The optimized geometry of sulfamethazine molecule was determined using two methods viz. density functional theory (DFT) and restricted Hartree-Fock (RHF) in the gas phase. Spectral analysis of grown crystal

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32

Noudem, P., D. Fouejio, C. D. D. Mveme, S. S. Zekeng, F. Tchangnwa Nya, and G. W. Ejuh. "Hartree-Fock and DFT studies of the optoelectronic, thermodynamic, structural and nonlinear optical properties of photochromic polymers containing styrylquinoline fragments." Materials Chemistry and Physics 281 (April 2022): 125883. http://dx.doi.org/10.1016/j.matchemphys.2022.125883.

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33

Pandey, Ankita, Abhishek Kumar Gupta, Shivani Gupta, Sarvesh Kumar Gupta, and Rajesh Kumar Yadav. "Electronic, Vibrational, and Structural Study of Polysaccharide Agar-Agar Biopolymer." Nano Hybrids and Composites 33 (October 11, 2021): 35–46. http://dx.doi.org/10.4028/www.scientific.net/nhc.33.35.

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Polysaccharide biopolymer Agar-Agar extracted from red algae is a natural and biodegradable polymer. It is a combination of agarose (a neutral and linear polymer, with repeated units of agarobiose) and a heterogeneous mixture of agaropectin (a charged sulfated polymer). In this study, a comparative study of structural vibrational and electrochemical properties of agar-agar biopolymer with two different methods HF (Hartree-Fock) and DFT (Density Functional Theory) using a basis set 631+G (d, p) is performed. The comparative structural study of agar-agar biopolymer by HF and DFT method has been

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34

LOPES, JULIANA FEDOCE, JÚLIO C. S. DA SILVA, WILLIAN R. ROCHA, WAGNER B. DE ALMEIDA, and HÉLIO F. DOS SANTOS. "QUANTUM CHEMICAL STUDY OF CISPLATIN-WATER COMPLEXES: AN INVESTIGATION OF ELECTRON CORRELATION EFFECTS." Journal of Theoretical and Computational Chemistry 10, no. 03 (2011): 371–91. http://dx.doi.org/10.1142/s0219633611006517.

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The interaction of cisplatin ([ Pt(NH3)2Cl2] ) with water was studied for distinct complexation modes aiming to investigate the level of calculation required to describe transition metal complexes of biological relevance, where large scale ab initio post-Hartree-Fock calculations are usually precluded. Coupled Cluster (CCSD(T)) single point calculations employing MP2 and MP4(SDQ) optimized geometries and good quality basis sets, using effective core potential for platinum atom, are reported as well as Density Functional Theory (DFT) results employing various exchange-correlation functional. Th

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Komulainen, J., R. S. Laitinen, and R. J. Suontamo. "A theoretical study of the 77Se NMR and vibrational spectroscopic properties of SenS8n ring molecules." Canadian Journal of Chemistry 80, no. 11 (2002): 1435–43. http://dx.doi.org/10.1139/v02-153.

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The structures and spectroscopic properties of SenS8n ring molecules have been studied by the use of ab initio molecular orbital techniques and density functional techniques involving Stuttgart relativistic large core effective core potential approximation with double zeta basis sets for valence orbitals augmented by two polarization functions for both sulfur and selenium. Full geometry optimizations have been carried out for all 30 isomers at the Hartree-Fock level of theory. The optimized geometries and the calculated fundamental vibrations and Raman intensities of the SenS8n molecules agr

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36

Polat, Aysegul Suzan, Ilkay Gumus, and Hakan Arslan. "Vibrational spectroscopic and Hirshfeld surface analysis of N,N'-(azanediylbis(2,1-phenylene))bis(2-chloropropanamide)." European Journal of Chemistry 10, no. 4 (2019): 386–402. http://dx.doi.org/10.5155/eurjchem.10.4.386-402.1921.

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The title molecule, N,N'-(azanediylbis(2,1-phenylene))bis(2-chloropropanamide) (LNNN) was synthesized and characterized by means of Hirshfeld surface analysis and vibrational (FT-IR and RAMAN) studies. Ab-initio Hartree-Fock (HF) and density functional theory (DFT; BLYP, B3LYP, B3PW91 and mPW1PW91) calculations were accomplished using 6-31G(d,p) and 6-311G(d,p) basis sets. The comparison of calculated bond lengths and angles with X-ray crystal structure shows sufficient agreement. The solid phase FT-IR and FT-RAMAN spectra of LNNN have been recorded in the regions 4000-525 cm-1 and 4000-50 cm-

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37

Belkhiri, Lotfi, Boris Le Guennic, and Abdou Boucekkine. "DFT Investigations of the Magnetic Properties of Actinide Complexes." Magnetochemistry 5, no. 1 (2019): 15. http://dx.doi.org/10.3390/magnetochemistry5010015.

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Over the past 25 years, magnetic actinide complexes have been the object of considerable attention, not only at the experimental level, but also at the theoretical one. Such systems are of great interest, owing to the well-known larger spin–orbit coupling for actinide ions, and could exhibit slow relaxation of the magnetization, arising from a large anisotropy barrier, and magnetic hysteresis of purely molecular origin below a given blocking temperature. Furthermore, more diffuse 5f orbitals than lanthanide 4f ones (more covalency) could lead to stronger magnetic super-exchange. On the other h

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Arivazhagan, M., and S. Jeyavijayan. "Vibrational spectroscopic, first-order hyperpolarizability and HOMO, LUMO studies of 1,2-dichloro-4-nitrobenzene based on Hartree–Fock and DFT calculations." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 79, no. 2 (2011): 376–83. http://dx.doi.org/10.1016/j.saa.2011.03.036.

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39

Nowek, Andrzej, and Jerzy Leszcz�nski. "Post-Hartree-Fock and DFT level studies on the Cl2CO ? Cl2 complex: Accurate molecular parameters, harmonic vibrational frequencies, and interaction energies." International Journal of Quantum Chemistry 60, no. 5 (1996): 1007–13. http://dx.doi.org/10.1002/(sici)1097-461x(1996)60:5<1007::aid-qua7>3.0.co;2-4.

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MA, LI, RAYMOND ATTA-FYNN, and ASOK K. RAY. "ELEMENTAL AND MIXED ACTINIDE DIOXIDES: AN AB INITIO STUDY." Journal of Theoretical and Computational Chemistry 11, no. 03 (2012): 611–29. http://dx.doi.org/10.1142/s021963361250040x.

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We present a systematic study of the electronic, geometric, and magnetic properties of the actinide dioxides, UO2 , PuO2 , AmO2 , U0.5Pu0.5O2 , U0.5Am0.5O2 and Pu0.5Am0.5O2 . For UO2 , PuO2 and AmO2 , both density functional and hybrid density functional theory (DFT and HDFT) have been used. The fractions of exact Hartree–Fock (HF) exchange chosen were 25% and 40% for the hybrid density functional. For U0.5Pu0.5O2 , U0.5Am0.5O2 and Pu0.5Am0.5O2 , only HDFT with 40% exact HF exchange was used. Each compound has been studied at the nonmagnetic, ferromagnetic and anti-ferromagnetic configurations

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41

Bielecki, Jakub, Dominik Dworak, Axel Jardin, et al. "Atomic models for description of high-Z impurities dynamics in tokamak plasmas – summary of HARMONIA project." EPJ Web of Conferences 306 (2024): 01032. http://dx.doi.org/10.1051/epjconf/202430601032.

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Since the year 2019, the project entitled „Study of the mutual dependence between Lower Hybrid current drive and heavy impurity transport in tokamak plasmas ”has been jointly executed by Polish (IFJ PAN) and French (CEA-IRFM) research teams. A particularly crucial topic studied within this project is the influence of not fully ionized high-Z impurities (e.g. tungsten ions) on suprathermal electrons dynamics. The influence can be studied using a Fokker-Planck solver. However, in this case, it is necessary to modify the electron-ion collision operator, in order to incorporate the efect of partia

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Lu, Le, та Ruimao Hua. "Dual XH–π Interaction of Hexafluoroisopropanol with Arenes". Molecules 26, № 15 (2021): 4558. http://dx.doi.org/10.3390/molecules26154558.

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The dual XH (OH and CH) hydrogen-bond-donating property of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and the strong dual XH–π interaction with arenes were firstly disclosed by theoretical studies. Here, the high accuracy post-Hartree–Fock methods, CCSD(T)/CBS, reveal the interaction energy of HFIP/benzene complex (−7.22 kcal/mol) and the contribution of the electronic correlation energy in the total interaction energy. Strong orbital interaction between HFIP and benzene was found by using the DFT method in this work to disclose the dual XH–π intermolecular orbital interaction of HFIP with benze

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43

Чернышев, В. А., В. С. Рюмшин та П. А. Агзамова. "Структура и динамика решетки MeF-=SUB=-2-=/SUB=- (Me=Ca, Sr, Ba, Pb) в кубической и орто-фазах: ab initio расчет". Физика твердого тела 61, № 1 (2019): 137. http://dx.doi.org/10.21883/ftt.2019.01.46904.188.

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AbstractThe MF_2 (M = Ca, Sr, Ba, Pb) crystals undergo a structural phase transition from the cubic to the orthorhombic phase in a range of 1–10 GPa. Although the cubic fluorites are well studied experimentally, there has been almost no information on their orthorhombic phase to date. Despite a few data on the Raman spectra available in the literature, there is still a lack of IR spectra of these structures. In this respect, this work aims to study the crystal structure and the phonon spectrum of MF_2 crystals (M = Ca, Sr, Ba, Pb) in both the cubic and orthorhombic phases, using the MO LKAO ap

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44

Linton, Kirsty A., Timothy G. Wright, and Nicholas A. Besley. "Quantum chemical study of the structure, spectroscopy and reactivity of NO + .(H 2 O) n =1−5 clusters." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2115 (2018): 20170152. http://dx.doi.org/10.1098/rsta.2017.0152.

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Quantum chemical methods including Møller–Plesset perturbation (MP2) theory and density functional theory (DFT) have been used to study the structure, spectroscopy and reactivity of NO + .(H 2 O) n =1−5 clusters. MP2/6-311++G** calculations are shown to describe the structure and spectroscopy of the clusters well. DFT calculations with exchange–correlation functionals with a low fraction of Hartree–Fock exchange give a binding energy of NO + .(H 2 O) that is too high and incorrectly predict the lowest energy structure of NO + .(H 2 O) 2 , and this error may be associated with a delocalization

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45

IRSAI, Izabella, Szilárd PESEK, and Radu SILAGHI-DUMITRESCU. "A critical review of computational efforts towards identifying secondary structure elements in polylactic acid (PLA)." Revue Roumaine de Chimie 68, no. 9 (2023): 473–79. http://dx.doi.org/10.33224/rrch.2023.68.9.08.

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Polylactic acid (PLA) may be regarded as an analogue of a poly-alanine oligo/polypeptide, where the amino group has been replaced by a hydroxyl. As a consequence, a series of studies have explored the possibility that PLA can adopt peptide-type secondary structures – i.e., repetitive structural patterns characterized by intramolecular hydrogen bonds between neighboring functional groups. To this end, computational techniques (molecular mechanics, semiempirical, Hartree-Fock, density functional theory DFT) geometry optimizations of isolated oligomers of lactic acid (generally ten-unit oligomers

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46

Akman, Feride. "Density functional theory (DFT) and Hartree–Fock (HF) calculations of potential p–vinylbenzyl chloride-based macroinitiator for atom transfer radical polymerization." Canadian Journal of Physics 94, no. 3 (2016): 290–304. http://dx.doi.org/10.1139/cjp-2015-0665.

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The spectroscopic properties of poly (styrene–co–p–vinylbenzyl chloride) (poly (St-co-VBC)) were investigated by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopic techniques. The molecular geometry and vibrational frequencies of macroinitiator, poly (St-co-VBC), were calculated by using density functional theory (DFT) and Hartree–Fock (HF) methods with 6–31 G+ (d, p) as a basis set. Calculated theoretical values are shown to be in good agreement with that of experimental values. An excellent harmony between the two data sets was verified. Besides, the expe

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47

Sainz-Díaz, C. Ignacio, Misaela Francisco-Márquez, and Annik Vivier-Bunge. "Adsorption of polyaromatic heterocycles on pyrophyllite surface by means of different theoretical approaches." Environmental Chemistry 8, no. 4 (2011): 429. http://dx.doi.org/10.1071/en11055.

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Environmental contextVolatile organic compounds can adsorb to the surfaces of silicates present in atmospheric aerosols, but the mechanisms and interactions are not well understood. We compare theoretical approaches for describing the adsorption of polyaromatic heterocycles to a model phyllosilicate surface. The enthalpy and spectroscopic data for this adsorption provide valuable information for future experimental studies on these atmospheric pollutants. AbstractThe adsorption of thiophene, benzothiophene and dibenzothiophene, as models of polyaromatic heterocycles, on the (001) surface of py

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48

Alotaibi, Moteb. "Investigating the Electronic Properties and Stability of Rh3 Clusters on Rutile TiO2 for Potential Photocatalytic Applications." Nanomaterials 14, no. 12 (2024): 1051. http://dx.doi.org/10.3390/nano14121051.

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Addressing the pressing needs for alternatives to fossil fuel-based energy sources, this research explores the intricate interplay between Rhodium (Rh3) clusters and titanium dioxide (TiO2) to improve photocatalytic water splitting for the generation of eco-friendly hydrogen. This research applies the density functional theory (DFT) coupled with the Hartree–Fock theory to meticulously examine the structural and electronic structures of Rh3 clusters on TiO2 (110) interfaces. Considering the photocatalytic capabilities of TiO2 and its inherent limitations in harnessing visible light, the potenti

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Eriksson, Leif A., C. Magnus Jansson, Donald R. Arnold, and Russell J. Boyd. "Article." Canadian Journal of Chemistry 76, no. 12 (1998): 1817–26. http://dx.doi.org/10.1139/v98-196.

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The cleavage reactions of the 1-butene and 4,4-dimethyl-1-pentene molecules and their cations, to form neutral and charged hydrocarbon products, are investigated using hybrid Hartree-Fock/density functional theory. In comparison with previous theoretical results (Du et al.), the density functional cleavage and ionization energies, including zero-point vibrational energy, lie in better agreement with experimental and thermochemical data. Assuming vertical ionization processes the mean absolute deviation (MAD) compared with experiment is 3.4 kcal/mol for the reaction sequences studied. Using adi

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50

Spiegel, Maciej, Andrzej Gamian, and Zbigniew Sroka. "A Statistically Supported Antioxidant Activity DFT Benchmark—The Effects of Hartree–Fock Exchange and Basis Set Selection on Accuracy and Resources Uptake." Molecules 26, no. 16 (2021): 5058. http://dx.doi.org/10.3390/molecules26165058.

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Polyphenolic compounds are now widely studied using computational chemistry approaches, the most popular of which is Density Functional Theory. To ease this process, it is critical to identify the optimal level of theory in terms of both accuracy and resource usage—a challenge we tackle in this study. Eleven DFT functionals with varied Hartree–Fock exchange values, both global and range-separated hybrids, were combined with 14 differently augmented basis sets to calculate the reactivity indices of caffeic acid, a phenolic acid representative, and compare them to experimental data or a high-lev

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