Sökning: "exchange repulsion"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden exchange repulsion.

  1. 1. A first-principles approach to protein–ligand interaction

    Författare :Pär Söderhjelm; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solvation; exchange repulsion; polarizable force fields; polarization; molecular mechanics; quantum chemistry; intermolecular interactions; protein–ligand interaction;

    Sammanfattning : It is still impossible to make an accurate, purely theoretical prediction of the free energy of a ligand binding to a protein in aqueous environment. The two main problems are the immense number of nuclear configurations contributing to the binding free energy and the impossibility to apply accurate quantum-chemical methods to such a large system, even for a single configuration. LÄS MER

  3. 2. Role of charge and spin fluctuations and their interplay in solids : A Green’s function approach

    Författare :Tor Sjöstrand; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Green’s function; correlations; collective excitations; screened interaction; electric polarization; orbital and spin magnetization; magnon-phonon interaction; Fierz ambiguity; time-dependent exchange-correlation potential;

    Sammanfattning : Due to the large number of electrons, solid state physics boils down to many-body approximations in which only selected types of collective excitations are taken into account, guided by the emergent properties of the material under study. In this thesis, the collective excitations of primary interest are electronic charge and spin fluctuations(plasmons and magnons) and nuclear charge fluctuations (phonons). LÄS MER

  4. 3. Interactions in Dye-sensitized Solar Cells

    Författare :Helena Greijer Agrell; Anders Hagfeldt; Gerrit Boschloo; Laurence Peter; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; solar cells; photovoltaics; dye-sensitized; mesoporous; nanostructured; Raman scattering; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : The interactions between the molecular constituents in dye-sensitized solar cells were studied with UV-VIS and IR spectroscopy, Raman scattering, conductivity and electron accumulation measurements.From stability studies of the dye, bis(tetrabutylammonium)cis-bis(thiocyanato) bis(2,2’-bipyridine-4-carboxylic acid, 4’-carboxylate) ruthenium(II), in the complete solar cell, the thiocyanate ion ligand was found to be lost from the dye. LÄS MER

  5. 4. Quantum Theory of Exciton-Exciton Interactions in Atomically Thin Semiconductors

    Författare :Daniel Erkensten; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; excitons; transition-metal dichalcogenides; many-body theory; van der Waals heterostructures; 2D materials;

    Sammanfattning : Atomically thin materials such as transition-metal dichalcogenides (TMDs) have emerged as an unprecedented platform for engineering future optoelectronic devices and studying exotic quantum phases of matter. In particular, the strong Coulomb interaction in these materials enables the formation of tightly-bound excitons, electron-hole pairs with neither purely fermionic nor bosonic character. LÄS MER

  7. 5. Interacting Dirac Matter

    Författare :Saikat Banerjee; Alexander V. Balatsky; Jens Paaske; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dirac; superconductor; magnon; interaction; Fermi liquid theory; renormalization; Fysik; Physics;

    Sammanfattning : The discovery of graphene in 2004 has led to a surge of activities focused on the theoretical and experimental studies of materials hosting linearly dispersive quasiparticles during the last decade. Rapid expansion in the list of materials having similar properties to graphene has led to the emergence of a new class of materials known as the Dirac materials. LÄS MER