Search for dissertations about: "analytic gradients"

Showing result 1 - 5 of 7 swedish dissertations containing the words analytic gradients.

2. 1. New Approaches to Large-Scale Electronic Structure Calculations

   Author : Francesco Aquilante; Beräkningskemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; orbital localization; electron correlation; analytic gradients; Cholesky decomposition; density fitting; quantum chemistry; Teoretisk kemi; kvantkemi;

   Abstract : Recent years have witnessed a growing interest of the scientific community for the use of ab initio and density functional theory methods in theoretical studies of molecules containing many atoms. However, the `scaling wall' of some of the most accurate of such methods is often an obstacle for their applicability to systems of real-life interest, e. READ MORE

4. 2. Hamiltonian systems with Poisson commuting integrals

   Author : Håkan Eliasson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The purpose of this thesis is to study Hamiltonian systems with Poisson commuting integrals near a stationary point - a situation appearing in many problems of classical mechanics.It turns out that these integrals, under fairly general conditions on their quadratic parts, become singular (their gradients become linearly dependent) on symplectic submanifolds, giving rise to invariant manifolds for the Hamiltonian system - the singular manifolds. READ MORE

5. 3. Numerical simulation of kinetic effects in ionospheric plasma

   Author : Bengt Eliasson; Bertil Gustafsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Abstract : In this thesis, we study numerically the one-dimensional Vlasov equation for a plasma consisting of electrons and infinitely heavy ions. This partial differential equation describes the evolution of the distribution function of particles in the two-dimensional phase space (x,v). READ MORE

6. 4. Observability and identifiability of nonlinear systems with applications in biology

   Author : Milena Anguelova; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Observability; identifiability; nonlinear systems; time delay; delay systems; state elimination; metabolism; conservation laws; signalling pathways.; signalling pathways.;

   Abstract : This thesis concerns the properties of observability and identifiability of nonlinear systems. It consists of two parts, the first dealing with systems of ordinary differential equations and the second with delay-differential equations with discrete time delays. READ MORE

7. 5. Some Mathematical Aspects of Thermo and Fluid Dynamics

   Author : Carl Fredrik Stein; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; swirling jets; vortex breakdown; conical self-similarity; Long s jet; Taylor s hypothesis; frozen turbulence hypothesis; advection velocity; conjugate heat transfer; asymptotic analysis; swirling jets;

   Abstract : This thesis contains mathematical treatments of three issues in thermo and fluid dynamics: swirling jets and vortex breakdown, Taylor's hypothesis and conjugate heat transfer. The work on swirling jets is focused on the study of the well-posedness of the conically self-similar free-vortex solutions to the Navier--Stokes equations. READ MORE