Search for dissertations about: "Hartree-Fock method"

Showing result 1 - 5 of 22 swedish dissertations containing the words Hartree-Fock method.

  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. Influence of Nuclear Structure on Decay Properties of Heavy Nuclei

    Author : Daniel Ward; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; alpha decay; hindrance factors; Skyrme-Hartree-Fock-Bogoliubov model; superheavy nuclei; fission yields; Brownian-shape motion; nuclear structure; nuclear level density; alpha decay; hindrance factors; Skyrme-Hartree-Fock-Bogoliubov model; superheavy nuclei; fission yields; Brownian-shape motion; nuclear structure; nuclear level density; Fysicumarkivet A:2017:Ward;

    Abstract : This dissertation deals with the effects of nuclear structure on the α-decay properties, and on the fission-yielddistributions from the decay of heavy nuclei. The nuclear-structure and decay properties of superheavynuclei is one of the central topics for investigation. READ MORE

  4. 4. Quantum Chemistry for Large Systems

    Author : Elias Rudberg; Pawel Salek; Christian Ochsenfeld; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; fast multipole method; density matrix purification; sparse matrices; Theoretical chemistry; Teoretisk kemi;

    Abstract : This thesis deals with quantum chemistry methods for large systems. In particular, the thesis focuses on the efficient construction of the Coulomb and exchange matrices which are important parts of the Fock matrix in Hartree-Fock calculations. READ MORE

  5. 5. Efficient Density Matrix Methods for Large Scale Electronic Structure Calculations

    Author : Anastasia Kruchinina; Emanuel H. Rubensson; Elias Rudberg; David Bowler; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; electronic structure; linear scaling; density matrix; density functional theory; Hartree-Fock; recursive polynomial expansion; density matrix purification; eigenvectors; molecular orbitals; stopping criteria; inverse factorization; matrix sparsity; parallelization; Scientific Computing; Beräkningsvetenskap;

    Abstract : Efficient and accurate methods for computing the density matrix are necessary to be able to perform large scale electronic structure calculations. For sufficiently sparse matrices, the computational cost of recursive polynomial expansions to construct the density matrix scales linearly with increasing system size. READ MORE