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Journal articles on the topic 'DFT. MP2'

Author: Grafiati

Published: 29 September 2021

Last updated: 30 July 2025

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1

LUKEŠ, VLADIMÍR, ROLAND ŠOLC, MARIO BARBATTI, HANS LISCHKA, and HARALD-FRIEDRICH KAUFFMANN. "TORSIONAL POTENTIALS AND FULL-DIMENSIONAL SIMULATION OF ELECTRONIC ABSORPTION SPECTRA OF para-PHENYLENEVINYLENE OLIGOMERS USING SEMIEMPIRICAL HAMILTONIANS." Journal of Theoretical and Computational Chemistry 09, no. 01 (2010): 249–63. http://dx.doi.org/10.1142/s0219633610005645.

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A systematic study of torsional potential curves in electronic ground state based on second-order Møller–Plesset energy (MP2), density functional theory (DFT), and Austin mode 1 (AM1) methods is presented for para-phenylenevinylene oligomers constructed from two to four aromatic rings. The semiempirical AM1 approach gives the correct location of potential energy minima in comparison with the reference MP2 calculations and literature data. However, the semiempirical AM1 energy barriers at perpendicular orientation are ca. 30% smaller than the MP2 ones. The DFT calculations indicate optimal plan

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2

Semrád, Hugo, Ctibor Mazal, and Markéta Munzarová. "Free Radical Isomerizations in Acetylene Bromoboration Reaction." Molecules 26, no. 9 (2021): 2501. http://dx.doi.org/10.3390/molecules26092501.

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The experimentally motivated question of the acetylene bromoboration mechanism was addressed in order to suggest possible radical isomerization pathways for the syn-adduct. Addition–elimination mechanisms starting with a bromine radical attack at the “bromine end” or the “boron end” of the C=C bond were considered. Dispersion-corrected DFT and MP2 methods with the SMD solvation model were employed using three all-electron bases as well as the ECP28MWB ansatz. The rate-determining, elimination step had a higher activation energy (12 kcal mol−1) in case of the “bromine end” attack due to interme

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3

Badawi, Hassan M., and Wolfgang Förner. "DFT and MP2 Study of the Molecular Structure and Vibrational Spectra of the Anticancer Agent Cyclophosphamide." Zeitschrift für Naturforschung B 67, no. 12 (2012): 1305–13. http://dx.doi.org/10.5560/znb.2012-0069.

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The possible conformations in the most stable structure of cyclophosphamide were investigated at the DFT-B3LYP and MP2/6-311G** levels of calculation. The axial structure is calculated to be lower in energy than the equatorial form of cyclophosphamide by 5 (MP2) to 6 (DFT) kcal mol-1 because of a very weak anomeric effect and weak conjugation. Further it is the same structure as the one found in the X-ray investigations both of the hydrate and of the anhydrous form. The computed DFT vibrational frequencies of the axial structure were used to analyze the infrared and Raman spectra using normal-

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4

Sirirak, Jitnapa, Narin Lawan, Marc W. Van der Kamp, Jeremy N. Harvey, and Adrian J. Mulholland. "Benchmarking quantum mechanical methods for calculating reaction energies of reactions catalyzed by enzymes." PeerJ Physical Chemistry 2 (May 20, 2020): e8. http://dx.doi.org/10.7717/peerj-pchem.8.

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To assess the accuracy of different quantum mechanical methods for biochemical modeling, the reaction energies of 20 small model reactions (chosen to represent chemical steps catalyzed by commonly studied enzymes) were calculated. The methods tested included several popular Density Functional Theory (DFT) functionals, second-order Møller Plesset perturbation theory (MP2) and its spin-component scaled variant (SCS-MP2), and coupled cluster singles and doubles and perturbative triples (CCSD(T)). Different basis sets were tested. CCSD(T)/aug-cc-pVTZ results for all 20 reactions were used to bench

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5

Sharma, Divya, and Martin J. Paterson. "The structure and UV spectroscopy of benzene–water (Bz–W6) clusters using time-dependent density functional theory." Photochem. Photobiol. Sci. 13, no. 11 (2014): 1549–60. http://dx.doi.org/10.1039/c4pp00211c.

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MP2, DFT and TD-DFT applied to benzene–(water)<sub>6</sub> clusters show how both perturb the electronic spectra of each other and give rise to new charge transfer features from the benzene to the water cluster.

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6

Fadda, Elisa, and Robert J. Woods. "Contribution of the empirical dispersion correction on the conformation of short alanine peptides obtained by gas-phase QM calculations." Canadian Journal of Chemistry 91, no. 9 (2013): 859–65. http://dx.doi.org/10.1139/cjc-2012-0542.

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In this work we analyze the effect of the inclusion of an empirical dispersion term to standard DFT (DFT-D) in the prediction of the conformational energy of the alanine dipeptide (Ala2) and in assessing the relative stabilities of short polyalanine peptides in helical conformations, i.e., α and 310 helices, from Ala4 to Ala16. The Ala2 conformational energies obtained with the dispersion-corrected GGA functional B97-D are compared to previously published high level MP2 data. Meanwhile, the B97-D performance on larger polyalanine peptides is compared to MP2, B3LYP and RHF calculations obtained

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7

Karttunen, Antti J., Denis Usvyat, Martin Schütz, and Lorenzo Maschio. "Dispersion interactions in silicon allotropes." Physical Chemistry Chemical Physics 19, no. 11 (2017): 7699–707. http://dx.doi.org/10.1039/c6cp08873b.

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8

Piccini, GiovanniMaria, Maristella Alessio, and Joachim Sauer. "Ab initio study of methanol and ethanol adsorption on Brønsted sites in zeolite H-MFI." Physical Chemistry Chemical Physics 20, no. 30 (2018): 19964–70. http://dx.doi.org/10.1039/c8cp03632b.

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9

Dobado, J. A., and José Molina. "Adenine−Hydrogen Peroxide System: DFT and MP2 Investigation." Journal of Physical Chemistry A 103, no. 24 (1999): 4755–61. http://dx.doi.org/10.1021/jp990671n.

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10

Beni, Alireza Salimi, Alireza Najafi Chermahini, Hashem Sharghi, and Setareh Mirzaei Monfared. "MP2, DFT and ab initio calculations on thioxanthone." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 82, no. 1 (2011): 49–55. http://dx.doi.org/10.1016/j.saa.2011.06.059.

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11

Srivastava, Santosh Kumar, and Vipin Bahadur Singh. "Spectroscopic signatures and structural motifs in isolated and hydrated serotonin: a computational study." RSC Advances 5, no. 36 (2015): 28141–57. http://dx.doi.org/10.1039/c5ra00827a.

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12

Rauwolf, Cordula, Achim Mehlhorn, and Jürgen Fabian. "Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods." Collection of Czechoslovak Chemical Communications 63, no. 8 (1998): 1223–44. http://dx.doi.org/10.1135/cccc19981223.

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Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis

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13

Sharma, Divya, and Martin J. Paterson. "Ground and excited states of naphthalene–water (naphtha–W6) clusters: a computational study." RSC Advances 5, no. 36 (2015): 28281–91. http://dx.doi.org/10.1039/c5ra01894c.

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14

Kanaki, Elisavet, Giuseppe Sansone, Lorenzo Maschio, and Beate Paulus. "The effect of electron correlation on the adsorption of hydrogen fluoride and water on magnesium fluoride surfaces." Physical Chemistry Chemical Physics 17, no. 28 (2015): 18722–28. http://dx.doi.org/10.1039/c5cp02017d.

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15

Badran, Ismail, Nashaat N. Nassar, Nedal N. Marei, and Azfar Hassan. "Theoretical and thermogravimetric study on the thermo-oxidative decomposition of Quinolin-65 as an asphaltene model molecule." RSC Advances 6, no. 59 (2016): 54418–30. http://dx.doi.org/10.1039/c6ra07761g.

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In this study, the thermal oxidation of an asphaltene model molecule, Quinolin-65, was investigated using the density functional theory (DFT) and the second-order Møller–Plesset (MP2) perturbation theory.

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16

Sheet, Salah H. M. "THEORETICAL STUDY FOR COMPARISON OF pKa OF A NUMBER OF SCHIFF BASES BY EMPLOYING PARAMETERS DERIVED FROM DFT AND MP2 METHOD." New Materials, Compounds and Applications 8, no. 1 (2024): 94–108. http://dx.doi.org/10.62476/nmca8194.

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The ionization constants of seven compounds derived from Schiff bases have been studied theoretically. In this study, the factors affecting the ionization constant pKa of Schiff bases were found, which are van der Waals forces, energy levels, hardness, chemical potential and spherical electrophile index by conducting a theoretical study of these compounds using two methods of quantum mechanics for the purpose comparison, which is the Ab-initio basic calculation methods. Two methods were chosen, which are the density function theory (DFT) method and the MP2 Mueller-Pleist perturbation theory me

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17

Lanza, Giuseppe, and Maria Assunta Chiacchio. "On the size, shape and energetics of the hydration shell around alkanes." Physical Chemistry Chemical Physics 23, no. 43 (2021): 24852–65. http://dx.doi.org/10.1039/d1cp02888j.

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18

Beni, Alireza Salimi, and Setareh Mirzaei Monfared. "DFT and MP2 calculations on new series of hydroxythioxanthones." Journal of Molecular Structure 1039 (May 2013): 8–21. http://dx.doi.org/10.1016/j.molstruc.2013.01.060.

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19

Quiñonero, David, Carolina Garau, Antonio Frontera, Pablo Ballester, Antoni Costa та Pere M. Deyà. "Structure and Binding Energy of Anion−π and Cation−π Complexes: A Comparison of MP2, RI-MP2, DFT, and DF-DFT Methods". Journal of Physical Chemistry A 109, № 20 (2005): 4632–37. http://dx.doi.org/10.1021/jp044616c.

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20

Flores, Jesus R., Karol Jankowski, and Romuald Słupski. "Application of MP2 Results in Comparative Studies of Semiempirical Ground-State Energies of Large Atoms." Collection of Czechoslovak Chemical Communications 68, no. 2 (2003): 240–52. http://dx.doi.org/10.1135/cccc20030240.

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To study the usefulness of second-order Møller-Plesset (MP2) correlation energies for ground states of closed-shell atoms (referred to as MP2/CA energies) in estimations of the total correlation energies of larger closed-shell atoms, we have considered atoms and ions containing from 10 to 86 electrons. First, it is demonstrated that for N-electron systems, 10 ≤ N ≤ 18, the MP2/CA energies provide very good approximations to the very accurate estimates of atomic correlation energies by Chakravorty and Davidson. Next, for systems with 10 ≤ N ≤ 54, comparisons are made with the semiempirical ener

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21

Skelton, A. A., N. Agrawal, and J. R. Fried. "Quantum mechanical calculations of the interactions between diazacrowns and the sodium cation: an insight into Na+ complexation in diazacrown-based synthetic ion channels." RSC Adv. 5, no. 68 (2015): 55033–47. http://dx.doi.org/10.1039/c4ra14000a.

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Quantum mechanical calculations were performed to study the conformational behavior and complexation between a sodium cation and a diazacrown (diaza-18-crown-6) using density functional theory (DFT), Møller–Plesset (MP2) and molecular mechanics methods.

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22

Nachtigallová, Dana, Markéta Davidová, and Petr Nachtigall. "Reliability of DFT Methods for Description of Cu Sites and Their Interaction with NO in Zeolites." Collection of Czechoslovak Chemical Communications 63, no. 8 (1998): 1202–12. http://dx.doi.org/10.1135/cccc19981202.

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The reliability of various DFT functionals for description of Cu sites and their interaction with NO in zeolites is tested. The dissociation energies of Cun+H2O and Cun+NO systems calculated with various DFT functionals are compared with those obtained at the MP2 and CCSD(T) levels of theory. It is concluded that hybrid density functional (B3LYP) gives reliable description of studied systems, while LDA seriously overestimates dissociation energies.

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23

Stortz, Carlos A., and Ariel M. Sarotti. "Exhaustive exploration of the conformational landscape of mono- and disubstituted five-membered rings by DFT and MP2 calculations." RSC Advances 9, no. 42 (2019): 24134–45. http://dx.doi.org/10.1039/c9ra03524a.

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The conformational landscape of 22 different non, mono-, and disubstituted compounds with a five-membered ring was thoroughly explored by ab initio (MP2) and DFT (B3LYP and M06-2X) methods with the 6-311+G** basis set.

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24

Gruber, Nadia, Lidia L. Piehl, Emilio Rubin de Celis, et al. "Amidinoquinoxaline N-oxides as novel spin traps." RSC Advances 5, no. 4 (2015): 2724–31. http://dx.doi.org/10.1039/c4ra14335c.

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A series of nitrones were synthesized and tested as novel spin traps. The adducts generated by CH<sub>3</sub> addition showed remarkably persistent signals. Their EPR features and kinetics were rationalised by DFT and MP2 calculations.

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25

Huang, Fang, Jinliang Jiang, Mingwei Wen, and Zhi-Xiang Wang. "Assessing the performance of commonly used DFT functionals in studying the chemistry of frustrated Lewis pairs." Journal of Theoretical and Computational Chemistry 13, no. 01 (2014): 1350074. http://dx.doi.org/10.1142/s0219633613500740.

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The benchmark study has assessed the performance of 18 density functional theory (DFT) functionals, including GGAs, hybrid-GGAs, meta-GGAs, and hybrid meta-GGAs, in predicting bonding strength, barrier height and structure for systems involving Lewis acids and bases. Three databases were built for the study, including 15 bonding enthalpies of dative bonds (DBH15), 10 reaction barriers (BH10) and 10 X-ray structures (XCS10). Wavefunction-based ab initio calculations were also carried out for comparisons. The benchmark data were computed at the CCSD(T)/BSI//MP2/BSI(BSI=aug-cc-pVTZ) level. The 6-

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26

Plessow, Philipp N., and Felix Studt. "Olefin methylation and cracking reactions in H-SSZ-13 investigated with ab initio and DFT calculations." Catalysis Science & Technology 8, no. 17 (2018): 4420–29. http://dx.doi.org/10.1039/c8cy01194j.

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The olefin cycle of the methanol-to-olefins process is investigated for the zeolite H-SSZ-13 using periodic, van-der-Waals corrected DFT calculations, together with MP2 corrections derived from cluster models, which are essential for accurate barriers.

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27

ROCHA, WILLIAN R., ÉDER S. XAVIER, JÚLIO C. S. DA SILVA, ROBERTA P. DIAS, HÉLIO F. DOS SANTOS, and WAGNER B. DE ALMEIDA. "AN EVALUATION OF QUANTUM CHEMICAL CALCULATIONS OF REACTION ENERGIES FOR CATALYTIC ACTIVATION PROCESSES: THE ACTIVATION OF PROPANE BY A RHODIUM CATALYST REVISITED." Journal of Theoretical and Computational Chemistry 11, no. 02 (2012): 297–312. http://dx.doi.org/10.1142/s0219633612500204.

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In this paper we report the state of the art CCSD(T)//MP2 ab initio calculations for the activation of propane by cyclopentadienyl carbonyl rhodium, (Cp)Rh(CO) , using the effective core potential of Hay and Wadt (LANL2DZ) for rhodium atom and the correlated consistent polarized valence double-ξ basis set (cc-pVDZ) for C , H and O atoms. The CCSD(T) energy values are used as reference to assess the effect of electron correlation on the reaction energies, as well as the performance of density functional theory (DFT) energy values using various functionals. An investigation on the accuracy of DF

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28

Labidi, N. S. "A DFT study of Hyper-Rayleigh Scattering (HRS) first hyperpolarizability of substituted polyene: Part (ii)." Journal of Fundamental and Applied Sciences 14, no. 1 (2023): 229–51. http://dx.doi.org/10.4314/jfas.v14i1.12.

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Several DFT functionals have been carried out to study the first hyperpolarizabilities βHRS of push-pull polyene as a function the basis sets, of electron correlation, of the size, of the frequency dispersion and the geometry. These calculations confirm the huge effects of electron correlation, the Møller– Plesset (MP2) results reproduces the values of the first hyperpolarizability obtained with the reference CCSD(T) level. Among density functional theory exchange- correlation functionals, B3LYP, M062X, B3P86 and CAM-B3LYP are comparable to the MP2 for characterizing the dynamic first hyperpol

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29

Al-Hokbany, N. S., A. A. Dahya, I. Kh Warad, et al. "Structural and Theoretical Studies of 2-amino-3-nitropyridine." E-Journal of Chemistry 9, no. 4 (2012): 2191–204. http://dx.doi.org/10.1155/2012/895240.

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Geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance of 2-amino-3-nitropyridine (ANP) were investigated by utilizingab-initio(MP2) and DFT(B3LYP) using 6-311++G(d,p) basis set. Geometrical parameters (bond lengths, bond angles and torsion angles) were computed and compared with the experimental values obtained using X-ray single crystal measurements of the title compound. IR spectra were obtained and assigned by vibrational analysis. Comparing the theoretically calculated values (bond lengths, bond and dihedral angles) using both B3LYP/6-311++G(

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30

Shephard, Michael J., and Michael N. Paddon-Row. "The porphyrin-C60 non-bonded interaction: an ab initio MO and DFT study." Journal of Porphyrins and Phthalocyanines 06, no. 12 (2002): 783–94. http://dx.doi.org/10.1142/s1088424602000907.

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The non-bonded interactions between a porphyrin molecule and a C 60 molecule, in the gas-phase, has been systematically investigated using various theoretical models. These are: (1) wavefunction-based methods, Hartree-Fock SCF (HF), second-order Møller-Plesset (MP2) theory, and the localized MP2 (LMP2) theory using the diatomics in molecules (DIM-LMP2) and triatomics in molecules (TRIM-LMP2) methods; (2) density functional theory (DFT), using non-local (BLYP, PW91), hybrid (B3LYP), and local (SVWN) functionals. Of the HF and DFT methods examined, corrected for BSSE using the counterpoise (CP)

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31

Hernández-Garcı́a, R. M., N. Barba-Behrens, R. Salcedo, and G. Höjer. "Theoretical study of 2-guanidinobenzimidazole. HF, MP2 and DFT calculations." Journal of Molecular Structure: THEOCHEM 637, no. 1-3 (2003): 55–72. http://dx.doi.org/10.1016/s0166-1280(03)00370-1.

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32

Willow, Soohaeng Yoo, Xiao Cheng Zeng, Sotiris S. Xantheas, Kwang S. Kim, and So Hirata. "Why Is MP2-Water “Cooler” and “Denser” than DFT-Water?" Journal of Physical Chemistry Letters 7, no. 4 (2016): 680–84. http://dx.doi.org/10.1021/acs.jpclett.5b02430.

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33

Gil, Diego M., María E. Tuttolomondo, Sebastian Blomeyer, Christian G. Reuter, Norbert W. Mitzel, and Aída Ben Altabef. "Gas-phase structure of 2,2,2-trichloroethyl chloroformate studied by electron diffraction and quantum-chemical calculations." Physical Chemistry Chemical Physics 18, no. 1 (2016): 393–402. http://dx.doi.org/10.1039/c5cp05295e.

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The molecular structure and conformational properties of 2,2,2-trichloroethyl chloroformate, ClC(O)OCH<sub>2</sub>CCl<sub>3</sub> were determined experimentally using gas-phase electron diffraction (GED) and theoretically based on quantum-chemical calculations at the MP2 and DFT levels of theory.

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Joshi, Meenakshi, and Tapan K. Ghanty. "Unprecedented stability enhancement of multiply charged anions through decoration with negative electron affinity noble gases." Physical Chemistry Chemical Physics 22, no. 24 (2020): 13368–72. http://dx.doi.org/10.1039/d0cp01478h.

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Noble gas inserted highly symmetric icosahedral B<sub>12</sub>Ng<sub>12</sub>F<sub>12</sub><sup>2−</sup> (Ng = Kr–Xe) dianions with exceptional electronic stability in the gas phase are predicted using DFT, MP2 and DLPNO-CCSD(T) based methods.

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Maurer, Simon A., Lucien Clin, and Christian Ochsenfeld. "Cholesky-decomposed density MP2 with density fitting: Accurate MP2 and double-hybrid DFT energies for large systems." Journal of Chemical Physics 140, no. 22 (2014): 224112. http://dx.doi.org/10.1063/1.4881144.

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36

ERKOÇ, ŞAKIR. "STRUCTURAL AND ELECTRONIC PROPERTIES OF MAGNESIUM DIBORIDE." International Journal of Modern Physics C 14, no. 04 (2003): 483–89. http://dx.doi.org/10.1142/s012918310300467x.

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Structural, electronic, and vibrational properties of magnesium diboride have been investigated by performing ab initio calculation within DFT level considering full MP2 correlation correction through B3LYP exchange-correlation functional. The structural, electronic, and vibrational properties of MgB 2 triatom have been calculated in its ground state.

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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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Rai, Krishna Bahadur, Nabin Kumar Teemilsina, and Bijay Siwakoti. "First principles study of structural equilibrium configuration of Ortho-, Meta-, and Para-chloroaniline molecules." Scientific World 17, no. 17 (2024): 7–18. http://dx.doi.org/10.3126/sw.v17i17.66414.

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This work has studied the ground state energy, binding energy, equilibrium geometry, charge distribution, and dipole moment of ortho-, meta-, and para-chloroanilines using a wide range of advanced theoretical methods including first-principles Hartree-Fock (HF), Mϕller-Plesset (MP) perturbation theory, Configuration Interaction (CI) and Density Functional Theory [DFT (B3LYP)] with basis sets 3-21G, 4-31G, 6-31G, 6-31G*, 6-31G**, 6-311G, 6-311G*, and 6-311G**. The trend in ground state energy is obtained in EDFT < EHF+MP3 < EHF+MP2 < ECISD < EHF. The calculated binding energies for

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39

Mikhailov, Oleg V., and Denis V. Chachkov. "Quantum-Chemical Prediction of Molecular and Electronic Structure of Carbon-Nitrogen Chemical Compound with Unusual Ratio Atoms: C(N20)." International Journal of Molecular Sciences 24, no. 6 (2023): 5172. http://dx.doi.org/10.3390/ijms24065172.

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Using various versions of quantum-chemical calculation, namely four versions of density functional theory (DFT), (DFT B3PW91/TZVP, DFT M06/TZVP, DFT B3PW91/Def2TZVP, and DFT M06/Def2TZVP) and two versions of the MP method (MP2/TZVP and MP3/TZVP), the existence possibility of the carbon-nitrogen-containing compound having an unusual M: nitrogen ratio of 1:20, unknown for these elements at present, was shown. Structural parameters data are presented; it was noted that, as may be expected, CN4 grouping has practically a tetrahedral structure, and the chemical bond lengths formed by nitrogen atoms

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40

HOOSHYAR, H., H. RAHEMI, K. A. DILMAGANI, and S. F. TAYYARI. "THEORETICAL VIBRATIONAL SPECTRA STUDIES: THE EFFECT OF RING SIZE ON THE CARBONYL VIBRATIONAL FREQUENCIES." Journal of Theoretical and Computational Chemistry 06, no. 03 (2007): 459–76. http://dx.doi.org/10.1142/s0219633607003209.

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In this paper, molecular structures and vibrational frequencies of cycloketone, cyclopropanone, cyclobutanone, cyclopentanone, and cyclohexanone have been investigated by density functional theory (DFT) and the second order Møller and Plesset (MP2) levels of theory, using 6-311G, 6-311G**, 6-311++G, and 6-311++G** basis sets. The calculations predict a planar structure for cyclopropanone. The cyclobutanone ring is puckered and according to the calculations at B3LYP/6-311++G** and MP2/6-311++G** levels of theory, it deviates from planarity by 5.0° and 15.7°, respectively. The calculated barrier

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41

Ruangchaithaweesuk, Songtham, Juthathip Chorkate, Thana Maihom, et al. "Combined Computational and Experimental Studies of Trans- and Cis-Isomers of Potassium Diaquabis(Oxalato)Chromate (III)." Key Engineering Materials 757 (October 2017): 103–7. http://dx.doi.org/10.4028/www.scientific.net/kem.757.103.

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The trans- and cis-isomers of potassium diaquabis(oxalato)chromate (III) were studied computationally and experimentally. The structures of trans- and cis-configurations of [Cr(H2O)2(C2O4)2]- were optimized by DFT methodology with various functionals namely: B3LYP, CAM-B3LYP, TPSS, PBE, M06-L and ωB97X-D along with the more sophisticated MP2 method. The calculations show that the most stable forms for both isomers are in quartet states. The results from all DFT methods reveal that the cis-isomer is literally more stable than the trans-isomer with the lower average relative energy of 2.1 kcal/m

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Ivanov, A. Yu, S. G. Stepanian, V. A. Karachevtsev, and L. Adamovicz. "Tautomers of 6-thiopurine in low-temperature Ar matrices: FTIR spectroscopy analysis and quantum mechanical calculations." Low Temperature Physics 48, no. 4 (2022): 301–10. http://dx.doi.org/10.1063/10.0009734.

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The structures and vibrational spectra of 6-thiopurine (6TP) molecules in an isolated state were studied by the spectroscopic and computational methods. FTIR spectra of 6TP molecules isolated in low-temperature Ar matrices (at 11 K) were obtained in the infrared range 3800–200 cm–1. The optimized structures of tautomers, model clusters and the population of tautomers were estimated by the DFT, MP2 and CCSD(T) methods. The vibrational spectra were calculated by the DFT/B3LYP method with different basis sets [6–311++G(df,pd), aug-cc-pVDZ, aug-cc-pVTZ] and the MP2/aug-cc-pVDZ/anharmonic method. I

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43

FÖRNER, WOLFGANG, and HASSAN M. BADAWI. "ANALYSIS OF THE VIBRATIONAL SPECTRA OF 3,4-DIHYDROXY- AND 4-HYDROXY-3-METHOXYPHENYLACETIC ACIDS AND THE RING BREATHING MODE IN THEIR RAMAN SPECTRA." Journal of Theoretical and Computational Chemistry 10, no. 05 (2011): 711–30. http://dx.doi.org/10.1142/s0219633611006748.

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The structural stability of 3,4-dihydroxyphenylacetic acid and 4-hydroxy-3-methoxyphenylacetic acid were investigated using the DFT-B3LYP and the ab initio MP2 methods together with the 6-311G** basis set. The two molecules were predicted at the DFT and MP2 levels of calculation to have the non-planar (np) forms as the lowest energy conformer of the acids. Another very low lying conformer of the former acid in the gas phase seems to play no role in the condensed phase. The observed spectral intensities of the acids were consistent with the np conformation being the predominant form at room tem

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44

Gholiee, Yasin, and Sadegh Salehzadeh. "MP2 and DFT studies on interaction of a halide anion with the fully protonated form of 1,4,7-triazacyclononane." Journal of Theoretical and Computational Chemistry 14, no. 01 (2015): 1550001. http://dx.doi.org/10.1142/s0219633615500017.

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Density functional theory (DFT) using PBE, PBE1PBE, B3P86, B97-1, and BHandHLYP functionals as well as MP2 calculations employing the TZVP basis set were used to study the formation of four host–guest complexes with formula [ H 3 L ⋯ X ]2+ ( X = F -, Cl -, Br -, and I -). The result of calculations on the structural parameters of [ H 3 L ⋯ Cl ]2+ shows that the calculated data with BHandHLYP functional have the best agreement with the experimental data and all five DFT methods give the better result than MP2. The largest amounts of interaction energies between the halide anions and protonated

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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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Lewars, E. "Orthogonene: A computational study of a strongly twisted alkene." Canadian Journal of Chemistry 81, no. 10 (2003): 1119–25. http://dx.doi.org/10.1139/v03-150.

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The strongly twisted (calculated dihedral angle 84°) alkene orthogonene (tetracyclo[8,2,2,02,7,03,10]tetradecene-2(3)) was studied at the DFT (B3LYP/6-31G*) and ab initio (HF/6-31G* and MP2(fc)/6-31G*) levels with a view to exploring the question of how realistic a synthetic objective it is, particularly in view of the fact that an attempt was made to synthesize it. Orthogonene is a relative minimum on the potential energy surface at the B3LYP/6-31G* and MP2(fc)/6-31G* levels, but is predicted to have a very low barrier (1.2 kJ mol1 from the B3LYP calculations) to rearrangement by a 1,2-carbo

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Bouteiller, Yves, Jean Christophe Poully, Charles Desfrançois, and Gilles Grégoire. "Evaluation of MP2, DFT, and DFT-D Methods for the Prediction of Infrared Spectra of Peptides." Journal of Physical Chemistry A 113, no. 22 (2009): 6301–7. http://dx.doi.org/10.1021/jp901570r.

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48

Czernek, Jiří, Jiří Brus, and Vladimíra Czerneková. "A computational inspection of the dissociation energy of mid-sized organic dimers." Journal of Chemical Physics 156, no. 20 (2022): 204303. http://dx.doi.org/10.1063/5.0093557.

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The gas-phase value of the dissociation energy ( D0) is a key parameter employed in both experimental and theoretical descriptions of noncovalent complexes. The D0 data were obtained for a set of mid-sized organic dimers in their global minima which was located using geometry optimizations that applied ample basis sets together with either the conventional second-order Møller–Plesset (MP2) method or several dispersion-corrected density-functional theory (DFT-D) schemes. The harmonic vibrational zero-point (VZP) and deformation energies from the MP2 calculations were combined with electronic en

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Rai, Krishna Bahadur, Rishi Ram Ghimire, Chandra Dhakal, Kiran Pudasainee, and Bijay Siwakoti. "Structural Equilibrium Configuration of Benzene and Aniline: A First-Principles Study." Journal of Nepal Chemical Society 44, no. 1 (2024): 1–15. http://dx.doi.org/10.3126/jncs.v44i1.62675.

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The present work describes the equilibrium configuration of aromatic compounds like benzene and aniline molecules using the first principle (ab initio) calculation method implemented by the Gaussian 98 programs. The ground state energy for benzene and aniline molecules obtained using the DFT (B3LYP) calculation is lower than that obtained with the HF+MP2 method which, in turn, is lower than that obtained with the HF calculation. The calculated values of bond length, bond angle, and dihedral angle for these molecules with HF, HF+MP2, and DFT (B3LYP) levels of calculation agree with each other w

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Presti, Davide, Alfonso Pedone, Maria Cristina Menziani, Bartolomeo Civalleri, and Lorenzo Maschio. "Oxalyl dihydrazide polymorphism: a periodic dispersion-corrected DFT and MP2 investigation." CrystEngComm 16, no. 1 (2014): 102–9. http://dx.doi.org/10.1039/c3ce41758a.

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