Sökning: "density matrices"
Visar resultat 1 - 5 av 47 avhandlingar innehållade orden density matrices.
1. Sparse Matrices in Self-Consistent Field Methods
Sammanfattning : 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. LÄS MER
2. Attosecond photoelectron interferometry: from wavepackets to density matrices
Sammanfattning : Through the advent of high-order harmonic generation and attosecond light pulses, photoionization dynamics has been studied on the attosecond time-scale, the intrinsic time-scale of such dynamics. When the electron leaves the atomic potential a phase shift is imprinted on the electron wavefunction. LÄS MER
3. Exploring the Set of Quantum States
Sammanfattning : Quantum mechanical properties of finite dimensional quantum systems are used within the field of quantum information. In this thesis the set of states (density matrices) for such systems is studied and described, largely in geometrical terms. LÄS MER
4. Quantum Chemistry for Large Systems
Sammanfattning : 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. LÄS MER
5. Parallelization of dynamic algorithms for electronic structure calculations
Sammanfattning : The aim of electronic structure calculations is to simulate behavior of complex materials by resolving interactions between electrons and nuclei in atoms at the level of quantum mechanics. Progress in the field allows to reduce the computational complexity of the solution methods to linear so that the computational time scales proportionally to the size of the physical system. LÄS MER
