Search for dissertations about: "Trygve Helgaker"

Found 2 swedish dissertations containing the words Trygve Helgaker.

  2. 1. Foundation of Density Functionals in the Presence of Magnetic Field

    Author : Andre Laestadius; Michael Benedicks; Trygve Helgaker; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Current density functional theory; Hohenberg-Kohn theorems; paramagnetic current density functionals; Kohn-Sham theory; Levy-Lieb functional; variational principle; N-representable; degeneracy; Mathematics; Matematik;

    Abstract : This thesis contains four articles related to mathematical aspects of Density Functional Theory.In Paper A, the theoretical justification of density methods formulated with current densities is addressed. It is shown that the set of ground-states is determined by the ensemble-representable particle and paramagnetic current density. READ MORE

  4. 2. Studies of Self-interaction Corrections in Density Functional Theory

    Author : Guangde Tu; Olav Vahtras; Trygve Helgaker; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; Teoretisk kemi;

    Abstract : The self-interaction error (SIE) in density functional theory (DFT) appears from the fact that the residual self-interaction in the Coulomb part and that in the exchange part do not cancel each other exactly. This error is responsible for the unphysical orbital energies of DFT and the failure to reproduce the potential energy curves of several physical processes. READ MORE