Sökning: "MCSCF"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet MCSCF.

  1. 1. Theoretical Description of Electronic Transitions in Large Molecular Systems in the Optical and X-Ray Regions

    Författare :Nanna Holmgaard List; Jacob Kongsted; Hans Jørgen Aagaard Jensen; Roberto Cammi; Jeppe Olsen; Jens Oddershede; Denmark University of Southern Denmark Chemistry and Biology Department of Physics; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Polarizable embedding; multiscale modeling; localized electronic transitions; response theory; QM MM; damped linear response; non-dipolar effects; light-matter interactions; multipole expansion; embedding potentials; local field effects; fluorescent proteins; computational chemistry; MCSCF; Theoretical Chemistry and Biology; Teoretisk kemi och biologi;

    Sammanfattning : The size and conformational complexity of proteins and other large systems represent major challenges for today's methods of quantum chemistry.This thesis is centered around the development of new computational tools to gain molecular-level insight into electronic transitions in such systems. LÄS MER

  2. 2. Spin-Spin and Spin-Orbit coupling studies of small species and magnetic system

    Författare :Sathya S R R Perumal; Olav Vahtras; Ulf Wahlgren; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; spin-spin; spin-orbit; biradical; mcscf; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : The spin of an electron often misleadingly interpreted as the classical rotationof a particle. The quantum spin distinguishes itself from classicalrotation by possessing quantized states and can be detected by its magneticmoment. The properties of spin and its collective behavior with otherfundamental properties are fascinating in basic sciences. LÄS MER

  3. 3. Extending the Reach of Accurate Wavefunction Methods

    Författare :Mickaël G. Delcey; Roland Lindh; Per-Åke Malmqvist; Martin Schütz; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; Density fitting; CASSCF; Analytical gradients; Photochemistry; X-ray spectroscopy; Kemi med inriktning mot kvantkemi; Chemistry with specialization in Quantum Chemistry;

    Sammanfattning : Multiconfigurational quantum chemistry methods, and especially the multiconfigurational self-consistent field (MCSCF) and multireference perturbation theory (MRPT2), are powerful tools, particularly suited to the accurate modeling of photochemical processes and transition metal catalysis. However, they are limited by their high computational cost compared to other methods, especially density functional theory. LÄS MER

  4. 4. Nonlinear Optical Properties of Fullerenes, Oligomers, and Solutions

    Författare :Patrick Norman; Hans Ågren; David M. Bishop; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This work presents development and applications of modern tools in ab initio quantum chemistry for obtaining linear and nonlinear response properties of molecules in the gas phase and in solution. The external perturbing fields are primarily electric in nature with frequencies in the optical region. LÄS MER

  5. 5. Photophysical Properties of Organic and Organometallic molecules

    Författare :Oscar Rubio Pons; KTH; []
    Nyckelord :molecule; two-photon absorption; singlet-triplet. spin-orbit; CASSCF; emission; phosphorescence; DFT; B3LYP;

    Sammanfattning : Highly correlated quantum chemical methods have been appliedto study the photophysical properties of substituted benzenes.With the inclusion of spin-orbit coupling, the phosphorescencesof these molecules have been calculated usingMulti-CongurationalSelf- Consistent Field (MCSCF) quadraticresponse theory. LÄS MER