Essays about: "Fock"
Showing result 1 - 5 of 27 essays containing the word Fock.
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1. A C++ Matrix library for computing the Gateaux derivative of the Fermi-Dirac operator
University essay from Uppsala universitet/Avdelningen för beräkningsvetenskapAbstract : Computing the Fermi-Dirac operator is done through recursive polynomial expansions, using the SP2 and SP2 Acc algorithms. The Gateaux derivative is computed for both schemes by mapping the zeroth and first order matrices onto a block upper triangular matrix, which is implemented in Python using Numpy arrays to store full matrices and in C++ by first constructing a basic matrix library to use as blocks in a later created block upper triangular matrix library which only directly references two blocks in a 2 x 2 block matrix. READ MORE
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2. Error propagation in nuclear models
University essay from Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionenAbstract : In this thesis we perform error analysis of a nuclear model based on density-functional theory developed in Lund. The Lund model allows us to perform calculations of nuclear spectra more efficiently by constructing a simple effective Hamiltonian reproducing the quadrupole deformation and pairing interaction strength parameters of a spherical Hartree-Fock reference functional. READ MORE
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3. The Bloch-Messiah theorem and its application to overlaps
University essay from Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionenAbstract : The Bogoliubov transformation is the starting point for the Hartree-Fock-Bogoliubov method and thus for many theoretical approaches that describe heavy nuclei. This transformation is based on two matrices, denoted by U and V, which are called Bogoliubov amplitudes. In this paper the properties of these matrices are investigated. READ MORE
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4. Reactivity increasement of prehydrolysis kraft pulp from Acacia crassicarpa and Eucalyptus hybrids
University essay from KTH/Träkemi och massateknologiAbstract : Syftet med detta examensarbete var att öka reaktiviteten hos förhydrolyserad kraftmassa genom att använda tidigare förhydrolysat och svavelsyra under förhydrolysen. Först bestämdes den kemiska sammansättningen av två olika vedråvaror (Acacia crassicarpa och Eucalyptushybrider) för att observera och korrelera med förhydrolysprocessen. READ MORE
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5. Accelerated Density Matrix Iterations Using Eigenvalue Gaps
University essay from Uppsala universitet/Institutionen för informationsteknologiAbstract : Density and Fock matrices play a significant role in electronic structure calculations, and there exist several methods to compute the density matrix from a given Fock matrix. One such method isdensity matrix purification, in which the eigenspectrum of the Fock matrix is scaled into the [0,1]interval and the Fock matrix is afterwards iterated with a sequence of polynomials that push theeigenvalues towards 1 and 0. READ MORE
