Sökning: "time-dependent density functional theory"

Visar resultat 21 - 25 av 41 avhandlingar innehållade orden time-dependent density functional theory.

1. 21. Photophysical Properties of Organic and Organometallic molecules

   Författare :Oscar Rubio Pons; KTH; []
   Nyckelord :molecule; two-photon absorption; singlet-triplet. spin-orbit; CASSCF; emission; phosphorescence; DFT; B3LYP;

   Sammanfattning : Highly correlated quantum chemical methods have been appliedto study the photophysical properties of substituted benzenes.With the inclusion of spin-orbit coupling, the phosphorescencesof these molecules have been calculated usingMulti-CongurationalSelf- Consistent Field (MCSCF) quadraticresponse theory. LÄS MER

3. 22. Theoretical Study on Chemical Structures and Stability of Molecules in Metallic Junctions

   Författare :Wei Hu; Yi Luo; Lasse Jensen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; SERS; IETS; Interface; Chemical Stability; Teoretisk kemi och biologi; Theoretical Chemistry and Biology;

   Sammanfattning : In this thesis, we focus on the structural identification of the interface using surface enhanced Raman spectroscopy (SERS) and inelastic electron tunnelling scattering (IETS). Two different molecular junctions, namely gold/ trans-1,2-bis (4-pyridyl) ethylene/gold junction and gold/4,4'-bipyridine/gold junctions in various conditions were studied and the corresponding configurations were determined. LÄS MER

4. 23. Hot-carrier generation and strong coupling in metal nanoparticles

   Författare :Jakub Fojt; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hot carriers; strong coupling; nanoparticles; nanoplasmonics;

   Sammanfattning : Metal nanoparticles are an emerging platform for energy applications such as photovoltaics, solar-to-fuel conversion and photocatalysis. Nanoparticles confine the oscillating electromagnetic field of visible light to very small volumes, which allows for efficient absorption and scattering of light in the solar spectral range. LÄS MER

5. 24. First principles modeling of soft X-ray spectroscopy of complex systems

   Författare :Barbara Brena; Yi Luo; Vincenzo Carravetta; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : The electronic structures of complex systems have been studied by theoretical calculations of soft x-ray spectroscopies like x-ray photoelectron spectroscopy, near edge x-ray absorption fine structure, and x-ray emission spectroscopies. A new approach based on time dependent density functional theory has been developed for the calculation of shake-up satellites associated with photoelectron spectra. LÄS MER

7. 25. Theoretical Studies of Raman Scattering

   Författare :Abdelsalam Mohammed; Hans Ågren; Luciano Frediani; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : Different theoretical approaches have been presented in this thesis to study the Raman scattering effect. The first one is response theory applied up to third order of polarization, where the determination of α, β and γ is used to calculate linear Raman scattering (resonance Raman scattering (RRS) and normal Raman scattering (NRS)), hyper Raman scattering (HRS) and coherent anti-Stokes Raman scattering (CARS), respectively. LÄS MER