Viser treff 200-219 av 527

    • Formative and Summative Automated Assessment with Multiple-Choice Question Banks 

      Beerepoot, Maarten (Journal article; Tidsskriftartikkel, 2023-07-18)
      Digital automated assessment is a valuable and time-efficient tool for educators to provide immediate and objective feedback to learners. Automated assessment, however, puts high demands on the quality of the questions, alignment with the intended learning outcomes, and the quality of the feedback provided to the learners. We here describe the development and use of a large number (N > 180) of ...
    • The four-component DFT method for the calculation of the EPR g-tensor using a restricted magnetically balanced basis and London atomic orbitals 

      Misenkova, Debora; Lemken, Florian; Repisky, Michal; Noga, Jozef; Malkina, Olga L.; Komorovsky, Stanislav (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-28)
      ABSTRACT Four-component relativistic treatments of the electron paramagnetic resonance g-tensor have so far been based on a common gauge origin and a restricted kinetically balanced basis. The results of such calculations are prone to exhibit a dependence on the choice of the gauge origin for the vector potential associated with uniform magnetic field and a related dependence on the basis set ...
    • Four-component relativistic 31P NMR calculations for: Trans -platinum(ii) complexes: Importance of the solvent and dynamics in spectral simulations 

      Castro, Abril C.; Fliegl, Heike; Cascella, Michele; Helgaker, Trygve; Repisky, Michal; Komorovsky, Stanislav; Medrano, María Ángeles; Quiroga, Adoración G.; Swart, Marcel (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-18)
      We report a combined experimental-theoretical study on the 31P NMR chemical shift for a number of trans-platinum(II) complexes. Validity and reliability of the 31P NMR chemical shift calculations are examined by comparing with the experimental data. A successful computational protocol for the accurate prediction of the 31P NMR chemical shifts was established for trans-[PtCl2(dma)PPh3] (dma = ...
    • Four-Component Relativistic Calculations in Solution with the Polarizable Continuum Model of Solvation: Theory, Implementation and Application to the Group 16 Dihydrides H2X (X= O, S, Se, Te, Po) 

      Di Remigio, Roberto; Bast, Radovan; Frediani, Luca; Saue, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-20)
    • Four-Component Relativistic Density Functional Theory Calculations of EPR g- and Hyperfine-Coupling Tensors Using Hybrid Functionals: Validation on Transition-Metal Complexes with Large Tensor Anisotropies and Higher-Order Spin-Orbit Effects 

      Gohr, Sebastian; Hrobárik, Peter; Repisky, Michal; Komorovsky, Stanislav; Ruud, Kenneth; Kaupp, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-04)
      The four-component matrix Dirac-Kohn-Sham (mDKS) implementation of EPR g- and hyperfine A-tensor calculations within a restricted kinetic balance framework in the ReSpect code has been extended to hybrid functionals. The methodology is validated for an extended set of small 4d1 and 5d1 [MEXn] q systems, and for a series of larger Ir(II) and Pt(III) d7 complexes (S=1/2) with particularly ...
    • Four-component relativistic density functional theory with the polarisable continuum model: application to EPR parameters and paramagnetic NMR shifts 

      Di Remigio, Roberto; Repisky, Michal; Komorovsky, Stanislav; Hrobárik, Peter; Frediani, Luca; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-01)
      The description of chemical phenomena in solution is as challenging as it is im- portant for the accurate calculation of molecular properties. Here, we present the implementation of the polarizable continuum model (PCM) in the four-component Dirac–Kohn–Sham density functional theory framework, o ↵ ering a cost-e ↵ ective way to concurrently model solvent and relativistic e ↵ ects. The ...
    • Four-Component Relativistic Density-Functional Theory Calculations of Nuclear Spin-Rotation Constants: Relativistic Effects in p-Block Hydrides 

      Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Demissie, Taye Beyene; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-01)
      We present an implementation of the nuclear spin–rotation (SR) constants based on the relativistic four-component Dirac–Coulomb Hamiltonian. This formalism has been implemented in the framework of the Hartree–Fock and Kohn–Sham theory, allowing assessment of both pure and hybrid exchange–correlation functionals. In the density-functional theory (DFT) implementation of the response equations, a ...
    • Four-component relativistic time-dependent density-functional theory using a stable noncollinear DFT ansatz applicable to both closed- and open-shell systems 

      Komorovsky, Stanislav; Cherry, Peter J.; Repisky, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-14)
      We present a formulation of relativistic linear response time-dependent density functional theory for the calculation of electronic excitation energies in the framework of the four-component Dirac-Coulomb Hamiltonian. This approach is based on the noncollinear <i>ansatz</i> originally developed by Scalmani and Frisch [J. Chem. Theory Comput. 8, 2193 (2012)] and improves upon the past treatment of ...
    • Fragment-Based Drug Discovery 

      Lund, Bjarte Aarmo (Journal article; Tidsskriftartikkel, 2015-06-13)
    • Free-Base Corrole Anion 

      Tarai, Arup; Mallick, Jyotiprakash; Conradie, Jeanet; Kar, Sanjib; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-30)
      Free-base corroles have long been known to be acidic, readily undergoing deprotonation by mild bases and in polar solvents. The conjugate base, however, has not been structurally characterized until now. Presented here is a first crystal structure of a freebase corrole anion, derived from tris(p-cyanophenyl)corrole, as the tetrabuylammonium salt. The low-temperature (100 K) structure reveals ...
    • From Diaminosilylenes to Silapyramidanes: Making Sense of the Stability of Divalent Silicon Compounds 

      Torstensen, Kristian; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-07)
      Since the discovery of decamethylsilicocene over three decades ago, chemists have successfully isolated a variety of divalent silicon compounds by orchestrating steric and electronic effects to their advantage. Two broad strategies of electronic stabilization appear to have been widely deployed, namely, π-conjugation as in diaminosilylenes and π-complexation as in decamethylsilicocene and ...
    • Full Breit Hamiltonian in the Multiwavelets Framework 

      Tantardini, Christian; Remigio, Roberto Di; Bjørgve, Magnar; Jensen, Stig Rune; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-01)
      New techniques in core–electron spectroscopy are necessary to resolve the structures of oxides of f-elements and other strongly correlated materials that are present only as powders and not as single crystals. Thus, accurate quantum chemical methods must be developed to calculate core spectroscopic properties in such materials. In this contribution, we present an important development in this ...
    • Fully Polarizable QM/Fluctuating Charge Approach to Two-Photon Absorption of Aqueous Solutions 

      Di Remigio, Roberto; Giovannini, Tommaso; Ambrosetti, Matteo; Cappelli, Chiara; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      We present the extension of the quantum/classical polarizable fluctuating charge model to the calculation of single residues of quadratic response functions, as required for the computational modeling of two-photon absorption cross sections. By virtue of a variational formulation of the quantum/classical polarizable coupling, we are able to exploit an atomic orbital-based quasienergy formalism to ...
    • Full‐length 16S rRNA gene classification of Atlantic salmon bacteria and effects of using different 16S variable regions on community structure analysis 

      Klemetsen, Terje; Willassen, Nils Peder; Karlsen, Christian René (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-04)
      Understanding fish‐microbial relationships may be of great value for fish producers as fish growth, development and welfare are influenced by the microbial community associated with the rearing systems and fish surfaces. Accurate methods to generate and analyze these microbial communities would be an important tool to help improve understanding of microbial effects in the industry. In this study, ...
    • Gauge-origin independent calculations of electric-field-induced second-harmonic generation circular intensity difference using London atomic orbitals 

      Anelli, Marco; Ringholm, Magnus; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
      We present the first gauge-origin independent calculations of the circular intensity difference (CID) in electric-field-induced second-harmonic generation (EFISHG), including all contributions up to the electric-quadrupole–magnetic-dipole level. A recursive, open-ended response theory framework in combination with the use of London atomic orbitals allows us to ensure gauge-origin independent results. ...
    • Gauge-origin independent calculations of Jones birefringence 

      Shcherbin, Dmitri; Thorvaldsen, Andreas johan; Jonsson, Dan Johan; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      We present the first gauge-origin independent formulation of Jones birefringence at the Hartree–Fock level of theory. Gauge-origin independence is achieved through the use of London atomic orbitals. The implementation is based on a recently proposed atomic orbital-based response theory formulation that allows for the use of both time- and perturbation-dependent basis sets [Thorvaldsen, Ruud, Kristensen, ...
    • General recurrence-relation generation scheme for molecular integral evaluation 

      Gao, Bin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-24)
      We develop a new scheme for evaluating different molecular integrals using Gaussian type orbitals. In this new scheme, the evaluation of integrals is performed in two steps during runtime. The first step is a top-down procedure that maps each recurrence relation into a jagged array (array of arrays), where each element of a member array represents either the final results or some intermediate integrals ...
    • Generalization of Intrinsic Orbitals to Kramers-Paired Quaternion Spinors, Molecular Fragments, and Valence Virtual Spinors 

      Senjean, Bruno; Sen, Souloke; Repisky, Michal; Knizia, Gerald; Visscher, Lucas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-08)
      Localization of molecular orbitals finds its importance in the representation of chemical bonding (and antibonding) and in the local correlation treatments beyond mean-field approximation. In this paper, we generalize the intrinsic atomic and bonding orbitals [G. Knizia, J. Chem. Theory Comput. 2013, 9, 11, 4834–4843] to relativistic applications using complex and quaternion spinors, as well as to ...
    • A generalized few-state model for the first hyperpolarizability 

      Alam, MD Mehboob; Beerepoot, Maarten; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-22)
      The properties of molecules depend on their chemical structure, and thus, structure–property relations help design molecules with desired properties. Few-state models are often used to interpret experimental observations of non-linear optical properties. Not only the magnitude but also the relative orientation of the transition dipole moment vectors is needed for few-state models of the non-linear ...
    • Genome mapping of seed-borne allergens and immunoresponsive proteins in wheat 

      Juhasz, Angela; Belova, Tatiana; Florides, Chris G; Maulis, Csaba; Fischer, Iris; Gell, Gyongyver; Birinyi, Zsofia; Ong, Jamie; Keeble-Gagnere, Gabriel; Maharajan, Amudha Deepalakshmi; Ma, Wujun; Gibson, Peter; Jia, Jizeng; Lang, Daniel; Mayer, Klaus F X; Spannagl, Manuel; Tye-Din, Jason A.; Appels, Rudi; Olsen, Odd-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-17)
      Wheat is an important staple grain for humankind globally because of its end-use quality and nutritional properties and its adaptability to diverse climates. For a small proportion of the population, specific wheat proteins can trigger adverse immune responses and clinical manifestations such as celiac disease, wheat allergy, baker’s asthma, and wheat-dependent exercise-induced anaphylaxis (WDEIA). ...