International Journal of Quantum Chemistry

Cover image for Vol. 117 Issue 7

Early View (Online Version of Record published before inclusion in an issue)

Impact Factor: 2.184

ISI Journal Citation Reports © Ranking: 2015: 17/35 (Physics Atomic Molecular & Chemical); 19/101 (Mathematics Interdisciplinary Applications); 77/144 (Chemistry Physical)

Online ISSN: 1097-461X

Associated Title(s): Journal of Computational Chemistry

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  1. 1 - 20
  1. FULL PAPER

    1. Comparison of density functionals for the study of the high spin low spin gap in Fe(III) spin crossover complexes

      Jitnapa Sirirak, Darunee Sertphon, Wasinee Phonsri, Phimphaka Harding and David J. Harding

      Version of Record online: 25 FEB 2017 | DOI: 10.1002/qua.25362

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      Spin crossover complexes represent a challenging computational problem with spin states close in energy. Here, DFT calculations are used to explore the impact of the functional and basis set on the spin state splitting, ΔE(HS-LS) in a series of Fe(III) compounds. The results show that a careful choice of basis set and functional are required to accurately predict ΔE(HS-LS). B3LYP*, commonly used in Fe(II) spin crossover systems, is found to be unsuitable for these Fe(III) complexes.

  2. FULL PAPERS

    1. Design of donor–acceptor–donor (D–A–D) type small molecule donor materials with efficient photovoltaic parameters

      Muhammad Irfan, Javed Iqbal, Sana Sadaf, Bertil Eliasson, Usman Ali Rana, Salah Ud-din Khan and Khurshid Ayub

      Version of Record online: 25 FEB 2017 | DOI: 10.1002/qua.25363

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      Four Donor–Acceptor–Donor (D–A–D) type molecules with triphenylamine as donor moiety, thiophene as bridge, and thiazolothiazole as acceptor unit were computationally designed. All the designed molecules have excellent photovoltaic parameters with respect to reference molecule “R” but among designed donor molecules, one manifests lowest band gap, frontier molecular orbital energy levels, and distinctive broad due to stronger electron withdrawing groups. Such substituents contribute to the red shifts of absorption spectra and better stabilities for designed molecules.

  3. FULL PAPER

    1. Development of spin-dependent relativistic open-shell Hartree–Fock theory with time-reversal symmetry (II): The restricted open-shell approach

      Masahiko Nakano, Ryota Nakamura, Junji Seino and Hiromi Nakai

      Version of Record online: 25 FEB 2017 | DOI: 10.1002/qua.25366

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      The Kramers-restricted open-shell HF (KROHF) method is an open-shell Hartree–Fock theory for spin-dependent two-component relativistic calculations. KROHF is formulated as a relativistic analogue of the nonrelativistic ROHF theory using time-reversal symmetry and quaternion algebra. In this formulation, the ambiguity of the Fock operator, which may lead to unphysical spinor energies, and the self-consistent field convergence behavior are discussed, together with the fundamental properties of total and spinor energies.

  4. FULL PAPERS

    1. Theoretical investigation toward organophosphine-catalyzed [3 + 3] annulation of Morita–Baylis–Hillman carbonates with azomethine imines: Mechanism, origin of stereoselectivity, and role of catalyst

      Wei Zhang, Yan Qiao, Yang Wang, Mingsheng Tang and Donghui Wei

      Version of Record online: 22 FEB 2017 | DOI: 10.1002/qua.25367

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      The mechanism and stereoselectivity of organophosphine-catalyzed [3 + 3] annulation reactions of MBH carbonates with C,N-cyclic azomethine imines is explored by means of first-principles calculations. Novel mechanistic information and a rationale for the stereoselectivity of the reaction is obtained and can be used to better understand this family of reactions. Theoretical results on these systems also provide valuable insights into rational design of efficient Lewis base-catalyzed C(sp2)[BOND]H activation/cycloadditions.

    2. Computational insight on the chalcone formation mechanism by the Claisen–Schmidt reaction

      Venelin Enchev and Aleksandar Y. Mehandzhiyski

      Version of Record online: 22 FEB 2017 | DOI: 10.1002/qua.25365

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      New insights in the reaction mechanism of the base-catalyzed Claisen–Schmidt condensation is obtained by MP2-level ab initio calculations. The proposed pathway to the synthesis of chalcone is composed of two reactions—the activation of the acetophenone by a removal of proton, and the attack of the formed acetophenone anion to the aromatic aldehyde. The first reaction proceeds in one step while the second is multisteps.

    3. The exact Fermi potential yielding the Hartree–Fock electron density from orbital-free density functional theory

      Kati Finzel and Paul W. Ayers

      Version of Record online: 22 FEB 2017 | DOI: 10.1002/qua.25364

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      Orbital-free density functional theory is a promising alternative to the more conventional Kohn–Sham DFT approach for large systems. The exact expression for the Fermi potential yielding the Hartree–Fock electron density within an orbital-free density functional formalism is derived. The Fermi potential is in this context given as the sum of the Pauli potential and the exchange potential. The exact exchange potential for an orbital-free density functional formalism is shown to be the Slater potential.

    4. Theoretical study of interaction of heteroaromatic compounds with a cluster model of kaolinite tetrahedral surface

      Liang Wang, Xing Wang, Ping Qian and Hong Guo

      Version of Record online: 20 FEB 2017 | DOI: 10.1002/qua.25352

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      Heteroaromatic hydrocarbons do not have apparent functional groups capable of interacting with the silica-oxide tetrahedral surface of kaolinite. Thus, questions remain concerning the mechanism of that absorption. Ab initio calculations on model clusters of the kaolinite tetrahedral surface demonstrate that the hydrogen bond interactions involving the C[BOND]H groups of heteroaromatic compounds and the oxygen atoms of kaolinite tetrahedral surface are among the key interactions for the adsorption.

    5. Theoretical prediction on the synthesis of 2,3-dihydropyridines through Co(III)-catalysed reaction of unsaturated oximes with alkenes

      Xiang-Biao Zhang, Bin-Bin Yu, Sheng-Meng Si and Song Wang

      Version of Record online: 15 FEB 2017 | DOI: 10.1002/qua.25353

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      Earth-abundant and cost effective Cobalt-based catalysts can replace the homologous group-9 rhodium-based ones. Insights on the synthesis reactions of 2,3-dihydropyridines, which are important starting materials for pharmaceuticals, from α,β-unsaturated oxime pivalates and alkenes can be provided by Density Functional Theory calculations. Electron-donating substituent groups on Cp* are found to increase the endergonicity and the apparent activation energy of the concerted metalation-deprotonation process, while electron-withdrawing substituent groups facilitate the reaction through the opposite effect.

  5. TUTORIAL REVIEWS

    1. Ill-defined chemical concepts: The problem of quantification

      Jörg Grunenberg

      Version of Record online: 14 FEB 2017 | DOI: 10.1002/qua.25359

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      This article argues the controversial idea that some of the contemporary publications in chemistry are characterized by a confusion of ideas and concepts, and in part ill definitions. Exactly those ill-defined concepts lead, in the opinion of the author, to never ending controversies in the literature.

  6. FULL PAPER

    1. Development of spin-dependent relativistic open-shell Hartree–Fock theory with time-reversal symmetry (I): The unrestricted approach

      Masahiko Nakano, Junji Seino and Hiromi Nakai

      Version of Record online: 10 FEB 2017 | DOI: 10.1002/qua.25356

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      Kramers-unrestricted Hartree–Fock (KUHF) method, which partly exploits time-reversal symmetry, is formulated with the use of quaternion algebra. Acceleration in self-consistent field convergence is significant enough to pursue KUHF as a viable alternative in spin-dependent two-component relativistic calculations of open-shell systems.

    2. You have full text access to this OnlineOpen article
      Benchmarking density functionals in conjunction with Grimme's dispersion correction for noble gas dimers (Ne2, Ar2, Kr2, Xe2, Rn2)

      Attila Kovács, Jan Cz. Dobrowolski, Sławomir Ostrowski and Joanna E. Rode

      Version of Record online: 9 FEB 2017 | DOI: 10.1002/qua.25358

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      Grimme's recent D3 dispersion correction has been applied successfully in quantum chemical modeling of weak interactions, however, its performance for noble gases has not been tested in detail yet. The present study reports the benchmarking of eleven popular exchange-correlational functionals extended with the D3 correction for noble gas interactions.

    3. Efficient protocol for quantum Monte Carlo calculations of hydrogen abstraction barriers: Application to methanol

      Ellen T. Swann, Michelle L. Coote, Amanda S. Barnard and Manolo C. Per

      Version of Record online: 9 FEB 2017 | DOI: 10.1002/qua.25361

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      Accurate calculations of hydrogen abstraction reaction barrier heights require high-level treatment of electron correlation effects but most methods capable of this scale poorly with system size. Using methanol as a test case, Quantum Monte Carlo methods are shown to be as accurate as large-basis coupled cluster theory but with much better scaling. Careful choices of methodological parameters are used to significantly reduce the cost of these calculations, without compromising accuracy.

    4. A Green's function approach to the nonrelativistic radial wave equation of hydrogen atom

      Faiz Ur Rahman and Rui-Qin Zhang

      Version of Record online: 7 FEB 2017 | DOI: 10.1002/qua.25360

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      The Lippmann-Schwinger type equation is solved for the nonrelativistic radial wave of hydrogen atom using Green's function and proposed wave function. The equation is integrated iteratively and outcome of the first four iterations are plotted against the standard radial wave as shown in figure for the 1s state. Resultant wave converges to the standard radial wave with the increasing number of iterations.

  7. FULL PAPERS

    1. Investigation of structural, magneto-electronic, and thermoelectric response of ductile SnAlO3 from high-throughput DFT calculations

      Shakeel Ahmad Khandy and Dinesh C. Gupta

      Version of Record online: 7 FEB 2017 | DOI: 10.1002/qua.25351

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      First-principles calculations allow the study of the electronic structure and related properties of newly designed electrode material, SnAlO3. Advantageous magnetic and electrical properties, good elastic properties, and thermoelectric coefficients make this oxide material a promising compound for electrode design.

    2. Coupled cluster calculations provide a one-to-one mapping between calculated and observed transition energies in the electronic absorption spectrum of zinc phthalocyanine

      Andrew J. Wallace, Bryce E. Williamson and Deborah L. Crittenden

      Version of Record online: 6 FEB 2017 | DOI: 10.1002/qua.25350

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      The optical and electronic properties of metallophthalocyanines have led to their widespread use as dyes, in light-emitting diodes and photovoltaics, and as photo-active agents in biomedical applications. Despite this, their electronic absorption spectra have been poorly understood until now. High level ab initio electronic structure methods are required to obtain a one-to-one mapping between computed and observed transitions within the spectrum of zinc phthalocyanine.

    3. The enhancing effects of molecule X (X = PH2Cl, SHCl, ClCl) on chalcogen–chalcogen interactions in cyclic trimers Y···Y···X (Y = SHCl, SeHCl)

      Lixin Mo, Yanli Zeng, Xiaoyan Li and Lingpeng Meng

      Version of Record online: 6 FEB 2017 | DOI: 10.1002/qua.25354

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      The chalcogen–chalcogen bonds formed in interacting SHCl (SeHCl) dimers, is strengthened in the cyclic trimers SHCl•••SHCl•••X and SeHCl•••SeHCl•••X, on addition of molecule X. Computational studies allow to compare the effects of different X molecules, and determine that X = PH2Cl yields the largest increase in chalcogen–chalcogen bond strength.

    4. Catalytic action of Mn-superoxide dismutase in scavenging superoxide radical anion by double hydrogen abstraction from dihydrolipoic acid: A theoretical study

      Ajit Kumar Prasad and Phool Chand Mishra

      Version of Record online: 3 FEB 2017 | DOI: 10.1002/qua.25355

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      Scavenging of superoxide radical anion ( inline image) by dihydrolipoic acid (diLA) in presence and absence of the enzyme manganese-superoxide dismutase (Mn-SOD) has been investigated employing density functional theory on a model for the active site of the enzyme. Mn-SOD is found to act as a strong catalyst in the scavenging reaction of inline image by diLA. diLA alone, without any catalyst, scavenges instead H2O2 via a barrierless reaction.

    5. Study of adiabatic connection in density functional theory with an accurate wavefunction for two-electron spherical systems

      Rabeet Singh Chauhan and Manoj K. Harbola

      Version of Record online: 3 FEB 2017 | DOI: 10.1002/qua.25344

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      An accurate semianalytic wavefunction is proposed for the Hookium which leads to energies that are as accurate as those from the Coupled cluster. An external potential is buildt such that the density of the system remains unchanged as strength parameter is varied. This approach thus provides a unified picture of adiabatic-connection for these systems based on an easy-to-use wavefunction.

    6. The role of hydroxyl groups in interchain interactions in cellulose Iα and Iβ

      Qingguo Feng, Raoul Noumbissi, Koushik Biswas and Hideya Koizumi

      Version of Record online: 2 FEB 2017 | DOI: 10.1002/qua.25357

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      Understanding the physical properties of the natural cellulose is important in industrial use. The hydrogen bonding network in the cellulose crystals contribute to these material properties greatly; however, the strength of the hydrogen bonds are not reported quantitatively. This article reports the theoretically determined strength of the interchain hydrogen bonds which directly correlate with the deformation in the plane perpendicular to the cellulose chain axis.

    7. Fluorescent dyes in the context of DNA-binding: The case of Thioflavin T

      Alessandro Biancardi, Tarita Biver and Benedetta Mennucci

      Version of Record online: 20 JAN 2017 | DOI: 10.1002/qua.25349

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      Thioflavin T is a dye characterized by a strong fluorescence light-up on binding to biosubstrates. Although this effect is known to be related to the inhibition of intramolecular torsion on excitation, the binding modes and their role in affecting photoinduced processes are by no means adequately understood. A combined molecular dynamics and quantum chemical modeling is used to study the tuning of the photophysical properties of Thioflavin T when moving from solution to DNA binding.

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