Sökning: "Born-Oppenheimer approximation"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Born-Oppenheimer approximation.

  1. 1. Four-Body Treatment of the Hydrogen-Antihydrogen System

    Författare :Henrik Stegeby; Piotr Froelich; Alejandro Saenz; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antimatter; antihydrogen; four-body system; Adiabatic approximation; Born-Oppenheimer; elastic scattering; stabilization method; resonance states; coupled arrangement channels; coupled rearrangement channels; Gaussian Expansion Method; Antimateria; antiväte; fyrkroppars system; adiabatisk approximation; stabilisationsmetoden; resonanstillstånd; spridningstillstånd; kopplade arrangemangskanaler; Quantum Chemistry; Kvantkemi;

    Sammanfattning : This thesis presents a nonadiabatic (4-body) description of the hydrogen-antihydrogen system at a nonrelativistic level. The properties of the system, the rearrangement processes and the possible existence of resonance states are investigated by using a variational method for coupled arrangement channels, the Gaussian Expansion Method, and the stabilization method. LÄS MER

  3. 2. Photoelectron Spectroscopy on HCl and DCl : Synchrotron Radiation Based Studies of Dissociation Dynamics

    Författare :Florian Burmeister; Eckart Rühl; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Photoelectron spectroscopy; HCl; DCl; Dissociation dynamics; Born-Oppenheimer approximation; Synchrotron radiation; Fysik; Physics; Fysik; fysik; Physics;

    Sammanfattning : Dissociation dynamics of the ionized molecules HCl and the deuterated system DCl has been studied in gas-phase using synchrotron based photoelectron spectroscopy (PES).The inner-valence "(4σ)-1" photoionization band for DCl and HCl was recorded using maximum resolution in order to probe an interference pattern between a dissociative and a bound electronic state. LÄS MER

  4. 3. Non-linear Spectroscopy of Conical Intersections

    Författare :Deependra Jadoun; Markus Kowalewski; Eva Lindroth; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kemisk fysik; Chemical Physics;

    Sammanfattning : Conical Intersections (CIs) in a molecule originate from the breakdown of the Born-Oppenheimer approximation when electronic states come close in energy. Ultrafast non-radiative decay channels open up in the vicinity of a CI, thus funneling a molecule from one electronic state to another. LÄS MER

  5. 4. Complexity and Error Analysis of Numerical Methods for Wireless Channels, SDE, Random Variables and Quantum Mechanics

    Författare :Håkon Hoel; Anders Szepessy; Helse Holden; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Wireless Channels; SDE; Monte Carlo Methods; Molecular Dynamics; Quantum Mechanics;

    Sammanfattning : This thesis consists of the four papers which consider different aspects of stochastic process modeling, error analysis, and minimization of computational cost.     In Paper I, we construct a Multipath Fading Channel (MFC) model for wireless channels with noise introduced through scatterers flipping on and off. LÄS MER

  7. 5. Theoretical studies of collisions involving the H2 reaction complex

    Författare :Johan Hörnquist; Åsa Larson; Eva Lindroth; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; fysik;

    Sammanfattning : In this thesis, collisions involving the H2 reaction complex are studied theoretically and the processes considered are mutual neutralization, double charge transfer, associative ionization, dissociative recombination and resonant ion-pair formation. These processes are examples of reactions that involve several excited states and where the Born-Oppenheimer approximation is not applicable. LÄS MER