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  • 1.
    Ahrén, Maria
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Selegård, Linnéa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A simple polyol-free synthesis route to Gd2O3 nanoparticles for MRI applications: an experimental and theoretical study2012In: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896X, Vol. 14, no 8Article in journal (Refereed)
    Abstract [en]

    Chelated gadolinium ions, e. g., GdDTPA, are today used clinically as contrast agents for magnetic resonance imaging (MRI). An attractive alternative contrast agent is composed of gadolinium oxide nanoparticles as they have shown to provide enhanced contrast and, in principle, more straightforward molecular capping possibilities. In this study, we report a new, simple, and polyol-free way of synthesizing 4-5-nm-sized Gd2O3 nanoparticles at room temperature, with high stability and water solubility. The nanoparticles induce high-proton relaxivity compared to Gd-DTPA showing r(1) and r(2) values almost as high as those for free Gd3+ ions in water. The Gd2O3 nanoparticles are capped with acetate and carbonate groups, as shown with infrared spectroscopy, near-edge X-ray absorption spectroscopy, X-ray photoelectron spectroscopy and combined thermogravimetric and mass spectroscopy analysis. Interpretation of infrared spectroscopy data is corroborated by extensive quantum chemical calculations. This nanomaterial is easily prepared and has promising properties to function as a core in a future contrast agent for MRI.

  • 2.
    Aidas, Kestutis
    et al.
    Vilnius University, Lithuania .
    Angeli, Celestino
    University of Ferrara, Italy .
    Bak, Keld L.
    University of Aarhus, Denmark .
    Bakken, Vebjorn
    University of Oslo, Norway .
    Bast, Radovan
    KTH Royal Institute Technology, Sweden .
    Boman, Linus
    EMGS ASA, Norway .
    Christiansen, Ove
    University of Aarhus, Denmark .
    Cimiraglia, Renzo
    University of Ferrara, Italy .
    Coriani, Sonia
    University of Trieste, Italy .
    Dahle, Pal
    Norwegian Comp Centre, Norway .
    Dalskov, Erik K.
    Systematic, Denmark .
    Ekstrom, Ulf
    University of Oslo, Norway .
    Enevoldsen, Thomas
    University of So Denmark, Denmark .
    Eriksen, Janus J.
    University of Aarhus, Denmark .
    Ettenhuber, Patrick
    University of Aarhus, Denmark .
    Fernandez, Berta
    University of Santiago de Compostela, Spain University of Santiago de Compostela, Spain .
    Ferrighi, Lara
    UiT Arctic University of Norway, Norway .
    Fliegl, Heike
    University of Oslo, Norway .
    Frediani, Luca
    UiT Arctic University of Norway, Norway .
    Hald, Kasper
    Danske Bank, Denmark .
    Halkier, Asger
    CSC Scandihealth, Denmark .
    Hattig, Christof
    Ruhr University of Bochum, Germany .
    Heiberg, Hanne
    Norwegian Meteorol Institute, Norway .
    Helgaker, Trygve
    University of Oslo, Norway .
    Christian Hennum, Alf
    Norwegian Def Research Estab, Norway .
    Hettema, Hinne
    University of Auckland, New Zealand .
    Hjertenaes, Eirik
    Norwegian University of Science and Technology, Norway .
    Host, Stinne
    University of Aarhus, Denmark .
    Hoyvik, Ida-Marie
    University of Aarhus, Denmark .
    Francesca Iozzi, Maria
    University of Oslo, Norway .
    Jansik, Branislav
    Technical University of Ostrava, Czech Republic .
    Jorgen Aa. Jensen, Hans
    University of So Denmark, Denmark .
    Jonsson, Dan
    UiT Arctic University of Norway, Norway .
    Jorgensen, Poul
    University of Aarhus, Denmark .
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Kirpekar, Sheela
    KVUC, Denmark .
    Kjrgaard, Thomas
    University of Aarhus, Denmark .
    Klopper, Wim
    Karlsruhe Institute Technology, Germany .
    Knecht, Stefan
    Swiss Federal Institute Technology, Switzerland .
    Kobayashi, Rika
    Australian National University, Australia .
    Koch, Henrik
    Norwegian University of Science and Technology, Norway .
    Kongsted, Jacob
    University of So Denmark, Denmark .
    Krapp, Andreas
    Jotun AS, Norway .
    Kristensen, Kasper
    University of Aarhus, Denmark .
    Ligabue, Andrea
    University of Modena and Reggio Emilia, Italy .
    B. Lutnaes, Ola
    Cisco Syst, Norway .
    I. Melo, Juan
    University of Buenos Aires, Argentina University of Buenos Aires, Argentina .
    V. Mikkelsen, Kurt
    University of Copenhagen, Denmark .
    H. Myhre, Rolf
    Norwegian University of Science and Technology, Norway .
    Neiss, Christian
    University of Erlangen Nurnberg, Germany .
    B. Nielsen, Christian
    Sun Chemistry, Denmark .
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Olsen, Jeppe
    University of Aarhus, Denmark University of So Denmark, Denmark .
    Magnus H. Olsen, Jogvan
    University of Aarhus, Denmark University of So Denmark, Denmark .
    Osted, Anders
    Koge Gymnasium, Denmark .
    J. Packer, Martin
    University of So Denmark, Denmark .
    Pawlowski, Filip
    Kazimierz Wielki University, Poland .
    B. Pedersen, Thomas
    University of Oslo, Norway .
    F. Provasi, Patricio
    Northeastern University, Argentina IMIT CONICET, Argentina .
    Reine, Simen
    University of Oslo, Norway .
    Rinkevicius, Zilvinas
    KTH Royal Institute Technology, Sweden KTH Royal Institute Technology, Sweden .
    A. Ruden, Torgeir
    Kjeller Software Commun, Norway .
    Ruud, Kenneth
    UiT Arctic University of Norway, Norway .
    V. Rybkin, Vladimir
    Karlsruhe Institute Technology, Germany .
    Salek, Pawel
    PSS9 Dev, Poland .
    C. M. Samson, Claire
    Karlsruhe Institute Technology, Germany .
    Sanchez de Meras, Alfredo
    University of Valencia, Spain .
    Saue, Trond
    University of Toulouse 3, France .
    P. A. Sauer, Stephan
    University of Copenhagen, Denmark .
    Schimmelpfennig, Bernd
    Karlsruhe Institute Technology, Germany .
    Sneskov, Kristian
    Danske Bank, Denmark .
    H. Steindal, Arnfinn
    UiT Arctic University of Norway, Norway .
    O. Sylvester-Hvid, Kristian
    Danish Technology Institute Nano and Microtechnol Prod, Denmark .
    R. Taylor, Peter
    University of Melbourne, Australia University of Melbourne, Australia .
    M. Teale, Andrew
    University of Nottingham, England .
    I. Tellgren, Erik
    University of Oslo, Norway .
    P. Tew, David
    University of Bristol, England .
    J. Thorvaldsen, Andreas
    University of Aarhus, Denmark .
    Thogersen, Lea
    CLC bio, Denmark .
    Vahtras, Olav
    KTH Royal Institute Technology, Sweden .
    A. Watson, Mark
    Princeton University, NJ 08544 USA .
    J. D. Wilson, David
    La Trobe University, Australia La Trobe University, Australia .
    Ziolkowski, Marcin
    Clemson University, SC USA .
    Agren, Hans
    KTH Royal Institute Technology, Sweden .
    The Dalton quantum chemistry program system2014In: WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE, ISSN 1759-0876, Vol. 4, no 3, p. 269-284Article in journal (Refereed)
    Abstract [en]

    Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, configuration-interaction, and coupled-cluster levels of theory. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients and Hessians are available for geometry optimizations, molecular dynamics, and vibrational studies, whereas magnetic resonance and optical activity can be studied in a gauge-origin-invariant manner. Frequency-dependent molecular properties can be calculated using linear, quadratic, and cubic response theory. A large number of singlet and triplet perturbation operators are available for the study of one-, two-, and three-photon processes. Environmental effects may be included using various dielectric-medium and quantum-mechanics/molecular-mechanics models. Large molecules may be studied using linear-scaling and massively parallel algorithms. Dalton is distributed at no cost from for a number of UNIX platforms.

  • 3.
    Cukras, Janusz
    et al.
    University of Trieste, Italy; University of Warsaw, Poland.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Rizzo, Antonio
    IPCF CNR, Italy.
    Rikken, Geert L. J. A.
    UPS, France; UPS, France.
    Coriani, Sonia
    University of Trieste, Italy; Aarhus University, Denmark.
    A complex-polarization-propagator protocol for magneto-chiral axial dichroism and birefringence dispersion2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 19, p. 13267-13279Article in journal (Refereed)
    Abstract [en]

    A computational protocol for magneto-chiral dichroism and magneto-chiral birefringence dispersion is presented within the framework of damped response theory, also known as complex polarization propagator theory, at the level of time-dependent Hartree-Fock and time-dependent density functional theory. Magneto-chiral dichroism and magneto-chiral birefringence spectra in the (resonant) frequency region below the first ionization threshold of R-methyloxirane and L-alanine are presented and compared with the corresponding results obtained for both the electronic circular dichroism and the magnetic circular dichroism. The additional information content yielded by the magneto-chiral phenomena, as well as their potential experimental detectability for the selected species, is discussed.

  • 4.
    Fahleson, Tobias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Coriani, Sonia
    University of Trieste, Italy .
    The magnetic circular dichroism spectrum of the C-60 fullerene2013In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 111, no 9-11, p. 1401-1404Article in journal (Refereed)
    Abstract [en]

    The magnetic circular dichroism spectrum of the C-60 fullerene has been determined with the use of Kohn-Sham density functional theory in conjunction with the CAM-B3LYP exchange-correlation functional. The experimental spectrum of Gasyna etal. [Chem. Phys. Lett. 183, 283 (1991)] covering the wavelength region above 200 nm is explained by the signal responses from the three lowest singlet states of T-1u symmetry.

  • 5.
    Fahleson, Tobias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Santoro, Fabrizio
    CNR, Italy.
    Improta, Roberto
    CNR, Italy.
    Coriani, Sonia
    University of Trieste, Italy; Aarhus University, Denmark.
    TD-DFT Investigation of the Magnetic Circular Dichroism Spectra of Some Purine and Pyrimidine Bases of Nucleic Acids2015In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 119, no 21, p. 5476-5489Article in journal (Refereed)
    Abstract [en]

    We present a computational study of the Magnetic circular dichroism (MCD) spectra in the 200-300 nm wavelength region of purine and its derivative hypoxanthine, as well as of the pyrimidine bases of nucleic acids uracil,thymine, and cytosine, Using the B3LYP and CAM-B3LYP functionals. Solvent effects, are investigated within the polarizable continuum model and by inclusion of explicit water molecules. In, general; the computed spectra are found to be in good agreement with the experimental ones, aprt from some overall blue shifts. Both the pseudo-A term shape of the MCD spectra of the purines and the B term shape of the spectra of pyrimidine base are reproduced. Our calculations also correctly reproduce the reversed phase of the MCD bands in purine compared to,that of its derivatives present in nucleic acids. Solvent effects are sizable and system specific,but they do not in general alter the qualitative shape of the spectra. The bands are dominated the-bright pi -greater than pi* transitions; and our calculations in solution nicely reproduce theft energy differences, improving the estimates obtained in the gas phase. Shoulders are predicted for purine and uracil due to n -greater than pi* excitations, but they are too weak to be observed in the. experiment.

  • 6.
    Holmgaard List, Nanna
    et al.
    University of Southern Denmark, Denmark.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Saue, Trond
    University of Toulouse 3, France.
    Jorgen Aagaard Jensen, Hans
    University of Southern Denmark, Denmark.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Chemistry. Linköping University, Faculty of Science & Engineering.
    Beyond the electric-dipole approximation: A formulation and implementation of molecular response theory for the description of absorption of electromagnetic field radiation2015In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 24, p. 244111-Article in journal (Refereed)
    Abstract [en]

    We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure of the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore.

  • 7.
    Kauczor, Joanna
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Efficient Calculations of Molecular Linear Response Properties for Spectral Regions2014In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 10, no 6, p. 2449-2455Article in journal (Refereed)
    Abstract [en]

    Molecular spectra can be determined from molecular response functions, by solving the so-called damped response equations using the complex polarization propagator approach. The overall structure of response equations is identical for variational wave functions such as the Hartree-Fock, multi-configuration self-consistent field, and Kohn-Sham density functional theory, and the key program module is the linear response equation solver. We present an implementation of the solver using the algorithm with symmetrized vectors, optimized for addressing spectral regions of a width of some 5-10 eV and a resolution below 0.1 eV. The work is illustrated by the consideration of UV-vis as well as near carbon K -edge absorption spectra of the C-60 fullerene. We demonstrate that it is possible to converge tightly response equations for hundreds of optical frequencies in resonance regions of the spectrum at a cost not much exceeding the solution of a single response equation in the nonresonant region. Our work is implemented in the molecular orbital based module of the Dalton program and serves as a documentation of the code distributed in the Dalton2013 release version.

  • 8.
    Kauczor, Joanna
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Christiansen, Ove
    Aarhus University, Denmark .
    Coriani, Sonia
    University of Trieste, Italy .
    Communication: A reduced-space algorithm for the solution of the complex linear response equations used in coupled cluster damped response theory2013In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 139, no 21, p. 211102-Article in journal (Refereed)
    Abstract [en]

    We present a reduced-space algorithm for solving the complex (damped) linear response equations required to compute the complex linear response function for the hierarchy of methods: coupled cluster singles, coupled cluster singles and iterative approximate doubles, and coupled cluster singles and doubles. The solver is the keystone element for the development of damped coupled cluster response methods for linear and nonlinear effects in resonant frequency regions.

  • 9.
    Kauczor, Joanna
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Saidi, Wissam A
    University of Pittsburgh, PA USA .
    Non-additivity of polarizabilities and van der Waals C-6 coefficients of fullerenes2013In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 138, no 11Article in journal (Refereed)
    Abstract [en]

    We present frequency-dependent polarizabilities and C-6 dipole-dipole dispersion coefficients for a wide range of fullerene molecules including C-60, C-70, C-78, C-80, C-82, and C-84. The static and dynamic polarizabilities at imaginary frequencies are computed using time-dependent Hartree-Fock, B3LYP, and CAM-B3LYP ab initio methods by employing the complex linear polarization propagator and are subsequently utilized to determine the C-6 coefficients using the Casimir-Polder relation. Overall, the C60 and C70 average static polarizabilities alpha(0) agree to better than 2% with linear-response coupledcluster single double and experimental benchmark results, and the C-6 coefficient of C-60 agrees to better than 1% with the best accepted value. B3LYP provides the best agreement with benchmark results with deviations less than 0.1% in alpha(0) and C-6. We find that the static polarizabilities and the C-6 coefficients are non-additive, and scale, respectively, as N1.2 and N2.2 with the number of carbon atoms in the fullerene molecule. The exponent for C-6 power-dependence on N is much smaller than the value predicted recently based on a classical-metallic spherical-shell approximation of the fullerenes.

  • 10.
    Pedersen, Morten
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, The Institute of Technology.
    Hedegard, Erik D.
    University of Southern Denmark, Denmark .
    Olsen, Jogvan Magnus H.
    University of Southern Denmark, Denmark .
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Kongsted, Jacob
    University of Southern Denmark, Denmark .
    Damped Response Theory in Combination with Polarizable Environments: The Polarizable Embedding Complex Polarization Propagator Method2014In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 10, no 3, p. 1164-1171Article in journal (Refereed)
    Abstract [en]

    We present a combination of the polarizable embedding (PE) scheme with the complex polarization propagator (CPP) method with the aim of calculating response properties including relaxation for large and complex systems. This new approach, termed PE-CPP, will benefit from the highly advanced description of the environmental electrostatic potential and polarization in the PE method as well as the treatment of near-resonant effects in the CPP approach. The PE-CPP model has been implemented in a Kohn-Sham density functional theory approach, and we present pilot calculations exemplifying the implementation for the UV/vis and carbon K-edge X-ray absorption spectra of the protein plastocyanin. Furthermore, technical details associated with a PE-CPP calculation are discussed.

  • 11.
    Santoro, Fabrizio
    et al.
    Istituto di Chimica dei Composti Organometallici (ICCOM-CNR), Italy .
    Improta, Roberto
    Istituto di Chimica dei Composti Organometallici (ICCOM-CNR).
    Fahleson, Tobias
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Coriani, Sonia
    Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Italy .
    Relative Stability of the L-a and L-b Excited States in Adenine and Guanine: Direct Evidence from TD-DFT Calculations of MCD Spectra2014In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 5, no 11, p. 1806-1811Article in journal (Refereed)
    Abstract [en]

    The relative position of L-a and L-b pi pi* electronic states in purine nucleobases is a much debated topic, since it can strongly affect our understanding of their photoexcited dynamics. To assess this point, we calculated the absorption and magnetic circular dichroism (MCD) spectra of adenine, guanine, and their nucleosides in gas-phase and aqueous solution,. exploiting recent developments in MCD computational technology within time-dependent density functional theory. MCD spectroscopy allows us to resolve the intense S-0 -greater than L-a transition from the weak S-0 -greater than L-b transition. The spectra obtained in water solution, by using B3LYP and CAM-B3LYP functionals and describing solvent effect by cluster models and by the polarizable continuum model (PCM), are in very good agreement with the experimental counterparts, thus providing direct and unambiguous evidence that the energy ordering predicted by TD-DFT, L-a less than L-b, is the correct one.

  • 12.
    Vaara, Juha
    et al.
    University of Oulu, Finland .
    Rizzo, Antonio
    CNR, Italy .
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Coriani, Sonia
    University of Trieste, Italy .
    Nuclear spin circular dichroism2014In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 140, no 13, p. 134103-Article in journal (Refereed)
    Abstract [en]

    Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.

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