Résumé

Restricted Hartree-Fock computations are reported for a methyl isocyanide
polymer (repeating unit -C=N-CH$_3$), whose most stable conformation is
expected to be a helical chain. The computations used a standard contracted Gaussian orbital set at the computational levels STO-3G, 3-21G, 6-31G, and 6-31G$^{**}$, and studies were made for two line-group configurations motivated by earlier work and by studies of space-filling molecular models:
(1) A structure of line-group symmetry $L9_5$, containing a 9-fold screw
axis with atoms displaced in the axial direction by 5/9 times the lattice constant, and (2) A structure of symmetry $L4_1$ that had been proposed, containing a four-fold screw axis with translation by 1/4 of the lattice constant. Full use of the line-group symmetry was employed to cause most of the computational complexity to depend only on the size of the asymmetric repeating unit. Data reported include computed bond properties, atomic charge distribution, longitudinal polarizability, band structure, and the convoluted density of states. Most features of the description were found insensitive to the level of computational approximation. The work also illustrates the importance of exploiting line-group symmetry to extend the range of polymer structural problems that can be treated computationally.

langueAnglais
Numéro d'articleDOI: 10.1021/acs.jpca.7b07403
Pages7993-8002
Nombre de pages10
journalJournal of Physical Chemistry A
Volume121
Date de mise en ligne précoce13 sept. 2017
étatPublié - 13 sept. 2017

mots-clés

    Citer ceci

    @article{cfafbde6c9554d2abcae0bb621869b94,
    title = "Electronic Band Structure of Helical Polyisocyanides",
    abstract = "Restricted Hartree-Fock computations are reported for a methyl isocyanidepolymer (repeating unit -C=N-CH$_3$), whose most stable conformation isexpected to be a helical chain. The computations used a standard contracted Gaussian orbital set at the computational levels STO-3G, 3-21G, 6-31G, and 6-31G$^{**}$, and studies were made for two line-group configurations motivated by earlier work and by studies of space-filling molecular models:(1) A structure of line-group symmetry $L9_5$, containing a 9-fold screwaxis with atoms displaced in the axial direction by 5/9 times the lattice constant, and (2) A structure of symmetry $L4_1$ that had been proposed, containing a four-fold screw axis with translation by 1/4 of the lattice constant. Full use of the line-group symmetry was employed to cause most of the computational complexity to depend only on the size of the asymmetric repeating unit. Data reported include computed bond properties, atomic charge distribution, longitudinal polarizability, band structure, and the convoluted density of states. Most features of the description were found insensitive to the level of computational approximation. The work also illustrates the importance of exploiting line-group symmetry to extend the range of polymer structural problems that can be treated computationally.",
    keywords = "polyisocyanides, Helical polymer, band structure, Electronic properties, Symmetry, line group, Ewald procedure, Fourier-space LCAO Hartree-Fock",
    author = "Fripiat, {Joseph G.} and Beno{\^i}t Champagne and Vincent Li{\'e}geois and Harris, {Franck E.}",
    year = "2017",
    month = "9",
    day = "13",
    language = "English",
    volume = "121",
    pages = "7993--8002",
    journal = "Journal of Physical Chemistry A",
    issn = "1089-5639",
    publisher = "American Chemical Society",

    }

    Electronic Band Structure of Helical Polyisocyanides. / Fripiat, Joseph G.; Champagne, Benoît; Liégeois, Vincent; Harris, Franck E. .

    Dans: Journal of Physical Chemistry A, Vol 121, DOI: 10.1021/acs.jpca.7b07403, 13.09.2017, p. 7993-8002.

    Résultats de recherche: Contribution à un journal/une revueArticle

    TY - JOUR

    T1 - Electronic Band Structure of Helical Polyisocyanides

    AU - Fripiat,Joseph G.

    AU - Champagne,Benoît

    AU - Liégeois,Vincent

    AU - Harris,Franck E.

    PY - 2017/9/13

    Y1 - 2017/9/13

    N2 - Restricted Hartree-Fock computations are reported for a methyl isocyanidepolymer (repeating unit -C=N-CH$_3$), whose most stable conformation isexpected to be a helical chain. The computations used a standard contracted Gaussian orbital set at the computational levels STO-3G, 3-21G, 6-31G, and 6-31G$^{**}$, and studies were made for two line-group configurations motivated by earlier work and by studies of space-filling molecular models:(1) A structure of line-group symmetry $L9_5$, containing a 9-fold screwaxis with atoms displaced in the axial direction by 5/9 times the lattice constant, and (2) A structure of symmetry $L4_1$ that had been proposed, containing a four-fold screw axis with translation by 1/4 of the lattice constant. Full use of the line-group symmetry was employed to cause most of the computational complexity to depend only on the size of the asymmetric repeating unit. Data reported include computed bond properties, atomic charge distribution, longitudinal polarizability, band structure, and the convoluted density of states. Most features of the description were found insensitive to the level of computational approximation. The work also illustrates the importance of exploiting line-group symmetry to extend the range of polymer structural problems that can be treated computationally.

    AB - Restricted Hartree-Fock computations are reported for a methyl isocyanidepolymer (repeating unit -C=N-CH$_3$), whose most stable conformation isexpected to be a helical chain. The computations used a standard contracted Gaussian orbital set at the computational levels STO-3G, 3-21G, 6-31G, and 6-31G$^{**}$, and studies were made for two line-group configurations motivated by earlier work and by studies of space-filling molecular models:(1) A structure of line-group symmetry $L9_5$, containing a 9-fold screwaxis with atoms displaced in the axial direction by 5/9 times the lattice constant, and (2) A structure of symmetry $L4_1$ that had been proposed, containing a four-fold screw axis with translation by 1/4 of the lattice constant. Full use of the line-group symmetry was employed to cause most of the computational complexity to depend only on the size of the asymmetric repeating unit. Data reported include computed bond properties, atomic charge distribution, longitudinal polarizability, band structure, and the convoluted density of states. Most features of the description were found insensitive to the level of computational approximation. The work also illustrates the importance of exploiting line-group symmetry to extend the range of polymer structural problems that can be treated computationally.

    KW - polyisocyanides

    KW - Helical polymer

    KW - band structure

    KW - Electronic properties

    KW - Symmetry

    KW - line group

    KW - Ewald procedure

    KW - Fourier-space LCAO Hartree-Fock

    M3 - Article

    VL - 121

    SP - 7993

    EP - 8002

    JO - Journal of Physical Chemistry A

    T2 - Journal of Physical Chemistry A

    JF - Journal of Physical Chemistry A

    SN - 1089-5639

    M1 - DOI: 10.1021/acs.jpca.7b07403

    ER -