International Journal of Quantum Chemistry

Cover image for Vol. 114 Issue 5

5 March 2014

Volume 114, Issue 5

Pages i–iv, 305–366

  1. Cover Image

    1. Top of page
    2. Cover Image
    3. Review
    4. Full Papers
    1. You have free access to this content
      Cover Image, Volume 114, Issue 5 (pages i–ii)

      Article first published online: 20 JAN 2014 | DOI: 10.1002/qua.24608

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      On page 305, José S. Duca and Jason B. Cross review the concept of combining information from electrostatic potential surfaces and nonbonding orbitals to determine the nature and directionality of intermolecular interactions, particularly those that are infrequently exemplified in the protein data bank. They present a different way of thinking about these interactions, generally applicable to other nontraditional and infrequently observed interactions, using the application of molecular modeling and structure-informed design (SID) to drug discovery. Strategies are offered for the incorporation of descriptions of electrostatic potential surfaces and nonbonding orbitals into the drug discovery process.

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      Inside Cover, Volume 114, Issue 5 (pages iii–iv)

      Article first published online: 20 JAN 2014 | DOI: 10.1002/qua.24609

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      The paper by Jonas Boström, Valera Veryazov, Francesco Aquilante, Thomas Bondo Pedersen, and Roland Lindh on page 321 discusses speeding up the calculation of atomic forces from correlated electronic structure theory using the Cholesky decomposition instead of conventional Gaussian two-electron integrals. The cover shows two molecules on a race track with atomic forces conventionally depicted as arrows and two watches. Cholesky and Boys were the individuals behind the decomposition and the Gaussian-type orbitals that paved the way for modern-day integral processing in quantum chemistry.

  2. Review

    1. Top of page
    2. Cover Image
    3. Review
    4. Full Papers
    1. You have free access to this content
      Quantum mechanical approaches to structurally informed design (pages 305–313)

      José S. Duca and Jason B. Cross

      Article first published online: 7 OCT 2013 | DOI: 10.1002/qua.24561

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      Ongoing improvements in computational throughput have made the application of quantum chemical methods more routine in drug discovery. Recent X-ray crystal structures of inhibitors exhibiting nontraditional interactions with their protein targets, through halogens or sulfur containing heterocycles, provide an opportunity to apply these techniques. This review discusses several examples of these types of interactions and outlines strategies for incorporating descriptions of electrostatic potential surfaces and non-bonding orbitals into the drug discovery process.

  3. Full Papers

    1. Top of page
    2. Cover Image
    3. Review
    4. Full Papers
    1. Valence orbital response to methylation of uracil (pages 314–320)

      Zejin Yang, Wenning Pang, Patrick Duffy and Feng Wang

      Article first published online: 7 OCT 2013 | DOI: 10.1002/qua.24562

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      The study of variations in chemical reactivity among various fragments of nucleic acids is important to modern biology and biochemistry. In this work, three valence orbital signatures of the methyl group in thymine with respect to uracil are identified, providing direct evidence that the newly formed orbitals can be uniquely determined despite varying chemical environments. A general conclusion about the chemical bindings of pyrimidine, cytosine, thymine, and uracil is obtained for the first time.

    2. Analytical gradients of the second-order Møller–Plesset energy using Cholesky decompositions (pages 321–327)

      Jonas Boström, Valera Veryazov, Francesco Aquilante, Thomas Bondo Pedersen and Roland Lindh

      Article first published online: 25 OCT 2013 | DOI: 10.1002/qua.24563

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      Analytical gradients for Cholesky decomposotion-based auxiliary basis sets using a full density fitting treatment instead of a conventional Hartree–Fock reference are presented. Although still suboptimal, the current implementation of this approach is shown to be 6–7 times more efficient than the conventional algorithm. The image demonstrates the reduced CPU times using this approach for the S22 test-set of molecules.

    3. Theoretical investigations on the superhalogen properties and interaction of PdOn (n = 1–5) species (pages 328–332)

      Ambrish Kumar Srivastava and Neeraj Misra

      Article first published online: 10 OCT 2013 | DOI: 10.1002/qua.24564

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      The molecular species that have electron affinities higher than the most electronegative halogens are referred to as superhalogens. Such species can interact with appropriate metal atoms, leading to the formation of complex compounds that have a very high oxidizing capability. In this work, superhalogen properties of PdOn species are investigated theoretically. It is concluded that PdOn for n ≥ 2 behave as superhalogens. The interaction of PdO2, a superhalogen, with a Ca atom forms a CaPdO2 complex.

    4. Theoretical studies of complexes between Hg(II) ions and l-cysteinate amino acids (pages 333–339)

      Joshua Watts, Elizabeth Howell and John K. Merle

      Article first published online: 10 OCT 2013 | DOI: 10.1002/qua.24565

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      Mercury is a toxic heavy metal that can cause health problems by disrupting cellular functions in organs, including the kidneys and brain. Current treatments for human mercury poisoning include chelation therapy using organic compounds that bind heavy metal ions, thereby facilitating excretion from the body. Better chelators are needed to improve on current therapies. This study examines the stabilities of cyteinyl-peptides as chelators of mercury(II) ions.

    5. Investigation of the change in the electronic properties of FeF3 by the introduction of oxygen using a molecular orbital method (pages 340–344)

      Yongseon Kim, Sujin Choi and Subin Kim

      Article first published online: 10 OCT 2013 | DOI: 10.1002/qua.24566

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      Because of its relatively high operating voltage, FeF3 is expected to be applied as a positive electrode material in lithium ion batteries. However, its electrical conductivity and ionic diffusivity must be improved before this material can find its way in industrial applications. First-principle calculations can provide insight into the electronic states of FeF3 and explain the improvement in electrical conductivity experienced when O is used in partial substitution of F.

    6. Backbiting and β-scission reactions in free-radical polymerization of methyl acrylate (pages 345–360)

      Shi Liu, Sriraj Srinivasan, Michael C. Grady, Masoud Soroush and Andrew M. Rappe

      Article first published online: 19 NOV 2013 | DOI: 10.1002/qua.24572

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      Backbiting and β-scission reactions can serve as “control knobs” for controlled polymerizations at high temperatures. In this work, multiple mechanisms of backbiting and β-scission reactions in free-radical polymerization of methyl acrylate are modeled computationally using different levels of theory. The benchmark study for large polymer systems and the approach of combining first-principles rate constant calculations and NMR spectrum modeling will improve the understanding of the complex free radical polymerization process.

    7. Israfil I. Guseinov: A pioneer of the quantum theory of atomic, molecular, and nuclear systems* (pages 361–366)

      Bahtiyar A. Mamedov

      Article first published online: 5 NOV 2013 | DOI: 10.1002/qua.24574

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      Born 80 years ago in Azerbaijan, physicist Israfil I. Guseinov contributed to the development of quantum chemistry with seminal research on subjects as broad as the Lorentz self-frictional field, Laguerre polynomials, exponential type orbitals, multicenter integrals, and nonrelativistic and relativistic quantum theories.

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