International Journal of Quantum Chemistry

Cover image for International Journal of Quantum Chemistry

5 June 2014

Volume 114, Issue 11

Pages i–iv, 689–754

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      Cover Image, Volume 114, Issue 11 (pages i–ii)

      Version of Record online: 17 APR 2014 | DOI: 10.1002/qua.24683

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      The development of new materials with exceptional nonlinear optical properties plays a key role for present-day electronic technology. The improvement of quantum-chemical approaches for the prediction of such properties as static and dynamic first and second hyperpolarizabilities has both practical and fundamental interest. On page 689 (DOI: 10.1002/qua.24617), Vladimir Rossikhin, Eugene Voronkov, Sergiy Okovytyy, Tetiana Sergeieva, Karina Kapusta, and Jerzy Leszczynski propose an efficient procedure for the construction of physically rationalized Slater-type basis sets for calculations of dynamic hyperpolarizability. Augmentation of minimal STO-3G basis sets by first- and second-order correction functions yields cost-effective STO##(II)-3Gel basis sets, which, at the DFT level, display better performance than well-known Gaussian-type basis sets.

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      Inside Cover, Volume 114, Issue 11 (pages iii–iv)

      Version of Record online: 17 APR 2014 | DOI: 10.1002/qua.24684

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      The through σ-bonds spin polarization mechanism in a radical, for example, in the ethyl radical, is described by Padeleimon Karafiloglou and Katerina Kyriakidou on page 696 (DOI: 10.1002/qua.24620) as a cooperative effect of two unpaired electrons in two atomic orbitals (AOs). When the AOs belong to the same atom (i.e., to spatially orthogonal orbitals), then the probability of simultaneously finding two unpaired electrons of parallel spins is greater than for antiparallel spins, in agreement with Hund's rule. The opposite holds when the two AOs contribute to a formal chemical bond. The green and pink images on the cover represent large and small probabilities, respectively.

  2. Full Papers

    1. Top of page
    2. Cover Image
    3. Full Papers
    1. Accurate calculations of dynamic first hyperpolarizability: Construction of physically justified slater-type basis sets (pages 689–695)

      Vladimir Rossikhin, Eugene Voronkov, Sergiy Okovytyy, Tetiana Sergeieva, Karina Kapusta and Jerzy Leszczynski

      Version of Record online: 6 FEB 2014 | DOI: 10.1002/qua.24617

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      For large molecules, the cost of calculations of the dynamic hyperpolarizability plays a critical role in the selection of the most appropriate theoretical approach for the task. A novel procedure for the expansion of the Slater-type basis set for these calculations yields cost-effective physically corrected basis sets, which at the DFT level display better performance than standard d-aug-cc-pvtz and Lpol-(FL,FS) Gaussian-type basis sets.

    2. Unpaired electrons, spin polarization, and bond orders in radicals from the 2-RDM in orbital spaces: Basic notions and testing calculations (pages 696–707)

      Padeleimon Karafiloglou and Katerina Kyriakidou

      Version of Record online: 10 FEB 2014 | DOI: 10.1002/qua.24620

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      Second-order reduced density matrices (2-RDM) are an important tool for the study of unpaired densities. The calculation and analysis of 2-RDM in radicals show the connection of various notions such as unpaired electrons, spin polarization, and bond orders. Within the framework of 2-RDM, the conventional α- and β-spin populations of radicals are split into paired and unpaired populations.

    3. Guest–host interaction in an aza crown analog (pages 708–719)

      Ranjita Das and Pratim Kumar Chattaraj

      Version of Record online: 26 FEB 2014 | DOI: 10.1002/qua.24648

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      A new aza-crown cluster with four inline image ions linked together using inline image ions is designed and proposed for synthesis by ab initio calculations. The host complex, inline image, can selectively bind metal ions. The favorable interaction energy and reaction free energy values suggest the stability of the host–guest complex. Different metal bound complexes exhibit different bonding patterns. The N[BOND]Ti bond exhibits a more covalent character than N[BOND]Li and N[BOND]Mg bonds.

    4. Probing the relationship between spin contamination and first hyperpolarizability: Open-shell Möbius anion (pages 720–724)

      Ying Gao, Hong-Liang Xu, Rong-Lin Zhong, Shi-Ling Sun and Zhong-Min Su

      Version of Record online: 24 FEB 2014 | DOI: 10.1002/qua.24649

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      Möbius structures exhibit a wide range of nonlinear optical properties, which make them interesting systems as potential optical switches. Several theoretical methods are compared for the study of the relationship between the spin contamination and the first hyperpolarizability of Möbius anions. The Hartree–Fock composition in various methods is found to have a large effect on the calculated value of both hyperpolarizability and spin contamination.

    5. Density functional theory studies of Si36H36 and C36H36 nanocages (pages 725–730)

      Jun Li, Hongcun Bai, Nini Yuan, Yuhua Wu, Yujia Ma, Ping Xue and Yongqiang Ji

      Version of Record online: 28 FEB 2014 | DOI: 10.1002/qua.24655

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      Unlike hydrogenated fullerene-[20] and [60] cages, none of Si36H36 and C36H36 exhibits a perfect spherical shape. The adjacent pentagons rule is invalid in the determination of the relative stability of Si36H36 and C36H36 nanocages. Small cages always give large energy gaps for carbon and silicon hydrides due to the quantum conferment effect. The lowest unoccupied molecular orbital of C36H36 is mainly distributed in the inner space of the cage, indicating the possibility to host metal atoms.

    6. Ab initio spectroscopic study for the NaRb molecule in ground and excited states (pages 731–747)

      Maha Chaieb, Héla Habli, Leila Mejrissi, Brahim Oujia and Florent Xavier Gadéa

      Version of Record online: 13 MAR 2014 | DOI: 10.1002/qua.24664

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      Heteronuclear alkali dimers, like NaRb, have applications in Bose–Einstein condensates, laser cooling, and photoassociative spectroscopy. Comprehensive first-principles modeling of the potential energy for all electronic states dissociating below the ionic limits of Na- and Rb+ helps in the correct assignment of vibrational and rotational quantum numbers from experiments, and inspires new pathways in cold ions trapping research.

    7. Dynamical properties of S(3P) + HD reaction on 13A″state and their quantum wavepacket calculation (pages 748–754)

      Shoubao Gao, Wei Wei, Bin Zheng, Yuzhi Song and Qingtian Meng

      Version of Record online: 14 MAR 2014 | DOI: 10.1002/qua.24666

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      S+H2/HD/D2 reactions are fundamental models for the study of elementary chemical reaction dynamics. The time-dependent wavepacket method is used to study reaction probabilities and integral cross sections of S(3P)+HD. The investigation shows an important effect of the vibrational excitation of HD in integral cross sections and a significant resonance feature in the reaction probabilities versus collision energy.