Search for dissertations about: "Hartree-Fock calculation"

Showing result 1 - 5 of 6 swedish dissertations containing the words Hartree-Fock calculation.

  1. 1. Matrix Algebra for Quantum Chemistry

    Author : Emanuel H. Rubensson; Pawel Salek; Stefan Goedecker; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; linear scaling; reduced complexity; electronic structure; density functional theory; Hartree-Fock; density matrix purification; congruence transformation; inverse factorization; eigenvalues; eigenvectors; numerical linear algebra; occupied subspace; canonical angles; invariant subspace; Theoretical chemistry; Teoretisk kemi;

    Abstract : This thesis concerns methods of reduced complexity for electronic structure calculations.  When quantum chemistry methods are applied to large systems, it is important to optimally use computer resources and only store data and perform operations that contribute to the overall accuracy. READ MORE

  2. 2. Sparse Matrices in Self-Consistent Field Methods

    Author : Emanuel Rubensson; Pawel Salek; Hans Ågren; Anders Niklasson; Axel Ruhe; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; sparse matrix; self-consistent field; Hartree-Fock; Density Functional Theory; Density Matrix Purification; Theoretical chemistry; Teoretisk kemi;

    Abstract : This thesis is part of an effort to enable large-scale Hartree-Fock/Kohn-Sham (HF/KS) calculations. The objective is to model molecules and materials containing thousands of atoms at the quantum mechanical level. HF/KS calculations are usually performed with the Self-Consistent Field (SCF) method. READ MORE

  3. 3. Gamow -Teller Beta Decay in Drip Line Nuclei

    Author : Fredrik Frisk; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gravitation; relativity; proton drip line; Gamow-Teller giant resonance; beta decay; Hartree-Fock calculation; prolate; oblate; deformed nuclei; Tamm-Dancoff approximation; Mathematical and general theoretical physics; quantum mechanics; classical mechanics; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Fysicumarkivet A:1997:Frisk;

    Abstract : Before radioactive ion beams became available, the Gamow-Teller (GT) giant resonance was studied using charge-exchange reactions such as (p,n) and (He,t). In beta-stable nuclei, which can be used as targets, the GT giant resonance lies above the ground state of the mother nucleus. READ MORE

  4. 4. Cluster model of disordered systems : application to doped semiconductors and a simple model polymer

    Author : Rolf G. Riklund; Linköpings universitet; []
    Keywords : ;

    Abstract : In this thesis we study with an extended cluster model calculation the combined effect of disorder and electron-electron interaction on the electronic structure of doped semiconductors and a simple model polymer chain. First a one-band model using a Hartree calculation is compared to other authors result for the impurity band using less realistic Hamiltonians. READ MORE

  5. 5. Theoretical Study of the Electronic Factor in Electron Transfer Reactions

    Author : Manuel Braga; Chalmers University of Technology; []
    Keywords : ;

    Abstract : The electronic factor D is calculated for a number of organic and biological electron transfer systems. Quantum chemical methods at different levels of accuracy are used: ab initio Hartree-Fock, broken-symmetry, and correlation-corrected methods such as multiconfigurational second-order perturbation theory, and also the semiempirical CNDO/S method for very large systems. READ MORE