Sökning: "exchange-correlation energy"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden exchange-correlation energy.

  1. 1. The many-electron energy in density functional theory : from exchange-correlation functional design to applied electronic structure calculations

    Författare :Rickard Armiento; Göran Grimvall; Jens K. Nörskov; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Sammanfattning : Att förutsäga egenskaper hos material och kemiska system är en viktig komponent för teoretisk och teknisk utveckling i fysik, kemi och biologi. Ett systems egenskaper styrs till stor del av dess elektrontillstånd. Datorprogram som baseras på täthetsfunktionalsteori kan beskriva elektronkonfigurationer mycket noggrant. LÄS MER

  3. 2. Interactions of molecules and solids within the density-functional theory

    Författare :Ylva Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; exchange-correlation energy; heteroepitaxy; effective-medium theory; van der Waals interactions; total energy; density-functional theory;

    Sammanfattning : .... LÄS MER

  4. 3. van der Waals Density Functionals

    Författare :Ylva Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; van der Waals molecules; physisorption; van der Waals interactions; density-functional theory; exchange-correlation energy; scanning-force microscopy; adhesion;

    Sammanfattning : Methods using local or semi local approximations (LDA, GGA etc.) for the exchange-correlation energy in the density-functional theory (DFT) do not include van der Waals interactions. LÄS MER

  5. 4. Van der Waals Interactions in Density Functional Theory

    Författare :Erika Hult; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; van der Waals interaction; exchange-correlation energy; adhesion; intermolecular forces; physisorption; density functional theory;

    Sammanfattning : Density functional theory is a very important method for calculating ground-state properties for atoms, molecules and solids. Albeit exact in principle, its implementation requires an approximation for the so-called exchange-correlation energy. LÄS MER

  7. 5. Interactions, initial states, and low-dimensional semiconductors

    Författare :Peter Jaksch; Stephanie M. Reimann-Wacker; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Q!uantum mechanical interactions; quantum point contact QPC ; quantum wires; exchange-correlation energy; Reilly model; quantum algorithms; Physics; Fysik;

    Sammanfattning : This thesis is concerned with different aspects of quantum mechanical interactions. The first part of the thesis focuses on their effects in low-dimensional semiconductors; the second part on one of their applications: quantum algorithms, which utilize superpositions created from quantum mechanical interactions. LÄS MER