Viser treff 517-525 av 525

    • Wavelet formulation of the polarizable continuum model. II. Use of piecewise bilinear boundary elements 

      Bugeanu, Monica; Di Remigio, Roberto; Mozgawa, Krzysztof; Reine, Simen Sommerfelt; Harbrecht, Helmut; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-27)
      The simplicity of dielectric continuum models has made them a standard tool in almost any Quantum Chemistry (QC) package. Despite being intuitive from a physical point of view, the actual electrostatic problem at the cavity boundary is challenging: the underlying boundary integral equations depend on singular, long-range operators. The parametrization of the cavity boundary should be molecular- ...
    • A weighted minimum distance using hybridization of particle swarm optimization and Bacterial Foraging 

      Muhammad Fuad, Muhammad Marwan (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • When Optimization Is Just an Illusion 

      Muhammad Fuad, Muhammad Marwan (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Bio-inspired optimization algorithms have been successfully applied to solve many problems in engineering, science, and economics. In computer science bio-inspired optimization has different applications in different domains such as software engineering, networks, data mining, and many others. However, some applications may not be appropriate or even correct. In this paper we study this phenomenon ...
    • X-ray absorption resonances near L2,3-edges from real-time propagation of the Dirac–Kohn–Sham density matrix 

      Kadek, Marius; Konecny, Lukas; Gao, Bin; Repisky, Michal; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-07)
      The solution of the Liouville–von Neumann equation in the relativistic Dirac–Kohn–Sham density matrix formalism is presented and used to calculate X-ray absorption cross sections. Both dynamical relaxation effects and spin–orbit corrections are included, as demonstrated by calculations of the X-ray absorption of SF6 near the sulfur L2,3-edges. We also propose an analysis facilitating the interpretation ...
    • X-ray Absorption Spectroscopy as a Probe of Ligand Noninnocence in Metallocorroles: The Case of Copper Corroles 

      Lim, Hyeongtaek; Kolle, Ekaney Thomas; Hedman, Britt; Hodgson, Keith O; Ghosh, Abhik; Solomon, Edward I. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-02)
      The question of ligand noninnocence in Cu corroles has long been a topic of discussion. Presented herein is a Cu K-edge X-ray absorption spectroscopy (XAS) study, which provides a direct probe of the metal oxidation state, of three Cu corroles, Cu[TPC], Cu[Br8TPC], and Cu[(CF3)8TPC] (TPC = meso-triphenylcorrole), and the analogous Cu(II) porphyrins, Cu[TPP], Cu[Br8TPP], and Cu[(CF3)8TPP] (TPP = ...
    • X-ray absorption spectroscopy of archetypal chromium porphyrin and corrole derivatives 

      Cao, Rui; Thomas, Kolle E.; Ghosh, Abhik; Sarangi, Ritimukta (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-29)
      A combination of Cr K-edge XAS and DFT calculations have been performed on archetypal chromium porphyrinoid complexes Cr<sup>IV</sup>[TMP]O (<b>2</b>) and Cr<sup>V</sup>[TPC]O (<b>3</b>), and the results have been compared to the reference compound Cr<sup>III</sup>[TPP]Cl (<b>1</b>), where TPP<sup>2−</sup>, TMP<sup>2−</sup>, and TPC<sup>3−</sup> are the anions of <i>meso</i>-tetraphenylporphyrin, ...
    • X-ray absorption spectroscopy of exemplary platinum porphyrin and corrole derivatives: metal- versus ligand-centered oxidation 

      Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-30)
      A combination of Pt L<sub>3</sub>-edge X-ray absorption spectroscopy (EXAFS and XANES) and DFT (TPSS) calculations have been performed on powder samples of the archetypal platinum porphyrinoid complexes Pt<sup>II</sup>[TpCF<sub>3</sub>PP], Pt<sup>IV</sup>[TpCF<sub>3</sub>PP]Cl<sub>2</sub>, and Pt<sup>IV</sup>[TpCF<sub>3</sub>PC](Ar)(py), where TpCF<sub>3</sub>PP<sup>2-</sup> = meso-tetrakis(p-tr ...
    • X-ray crystal structure of Vibrio alkaline phosphatase with the non-competitive inhibitor cyclohexylamine 

      Ásgeirsson, Bjarni; Markússon, Sigurbjörn; Hlynsdóttir, Sigríður S.; Helland, Ronny; Hjörleifsson, Jens G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-15)
      <i>Background</i> - <i>Para</i>-nitrophenyl phosphate, the common substrate for alkaline phosphatase (AP), is available as a cyclohexylamine salt. Here, we report that cyclohexylamine is a non-competitive inhibitor of APs.<br><br> <i>Methods</i> - Cyclohexylamine inhibited four different APs. Co-crystallization with the cold-active <i>Vibrio</i> AP (VAP) was performed and the structure solved.<br><br> ...
    • β-Octabromo- and β-Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands 

      Kolle, Ekaney Thomas; Beavers, Christine M.; Gagnon, Kevin J.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-26)
      Presented herein is a study of the acid-induced demetalation of two sterically hindered copper corroles, Cu b-octabromomeso-triphenylcorrole (Cu[Br8TPC]) and b-octakis(trifluoromethyl)-meso-tris(p-methoxyphenyl)corrole (Cu[(CF3 )8TpOMePC]). Unlike reductive demetalation, which affords the free-base boctabromocorrole, demetalation of Cu[Br8TPC] under nonreductive conditions (CHCl3 /H2SO4 ) ...