Sökning: "molecular orbitals"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden molecular orbitals.

  1. 1. Fingerprints of light-induced molecular transients : from quantum chemical models of ultrafast x-ray spectroscopy

    Författare :Jesper Norell; Michael Odelius; Sang-Kil Son; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; time-resolved x-ray spectroscopy; quantum chemistry; electronic structure; multi-configurational self-consistent field; density functional theory; molecular dynamics; Born-Oppenheimer dynamics; non-adiabatic dynamics; proton-transfer; charge-transfer; solvatization; Dyson orbital; teoretisk fysik; Theoretical Physics;

    Sammanfattning : Absorption of sunlight generates renewable electricity and powers the growth of plants, but also causes severe damage both to synthetic materials and biological tissue. The wildly varying outcomes of these light-induced processes are ultimately determined by much slighter differences in their underlying reaction pathways, induced by the transient properties of short-lived and miniscule molecules; a powerful approach to their detection and characterization is offered by ultrafast x-ray spectroscopy, with identification of spectral fingerprints and further guidance from quantum chemical models. LÄS MER

  2. 2. Ultrafast Probing of CO Reactions on Metal Surfaces : Changes in the molecular orbitals during the catalysis process

    Författare :Jörgen Gladh; Henrik Öström; Nils Mårtensson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hetrogenous catalysis; CO; transition metals; Ultrafast probing; oxidation; desorption; dissociation; kemisk fysik; Chemical Physics;

    Sammanfattning : This thesis presents experimental studies of three different chemical reaction steps relevant for heterogeneous catalysis: dissociation, desorption, and oxidation. CO on single-crystal metal surfaces was chosen as the model systems. LÄS MER

  3. 3. Synchrotron radiation spectroscopy of molecular dynamics beyond the valence shell

    Författare :Emilio Melero Garcia; Elisabeth Rachlew Källne; Nora Berrah; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular physics; Molekylfysik;

    Sammanfattning : This thesis presents experimental results on molecular spectroscopy of gas phase molecules using synchrotron radiation. It deals mainly with dynamical processes following resonant excitation of electrons from core and inner-valence shells of the following systems H2O, H2, SF6 and CD4. LÄS MER

  4. 4. The Electronic Structure of Organic Molecular Materials : Theoretical and Spectroscopic Investigations

    Författare :Iulia Emilia Brumboiu; Barbara Brena; Biplab Sanyal; Olle Eriksson; Jakob Schiøtz; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; materials theory; electronic structure; photoelectron spectroscopy; near-edge X-ray absorption fine structure; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Materialvetenskap; Materials Science;

    Sammanfattning : In the present thesis the electronic properties of two organic molecules were studied by means of density functional theory (DFT) in connection to their possible applications in organic photovoltaics and molecular spintronics respectively.The first analysed system is the C60 derivative PCBM extensively used in polymer solar cells for the charge separation process. LÄS MER

  5. 5. Computational Atomic Structures Toward Heavy Element Research

    Författare :Sacha Schiffmann; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atoms; electron correlation; relativity; Quantum mechanics; calculations; natural orbitals; isotope shifts; hyperfine structures; transition parameters; Landé g factor; Fysicumarkivet A:2021:Schiffmann;

    Sammanfattning : We are interested in complex electronic structures of various atomic and ionics systems. We use an ab initioapproach, the multiconfigurational Dirac-Hartree-Fock (MCDHF), to compute atomic structures and properties. LÄS MER