Sökning: "QUANTUM MOLECULAR-DYNAMICS"

Visar resultat 1 - 5 av 94 avhandlingar innehållade orden QUANTUM MOLECULAR-DYNAMICS.

1. 1. Algorithms for Molecular Dynamics Simulations

   Författare :Fredrik Hedman; Aatto Laaksonen; Tom Darden; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; MD; first principles molecular dynamics; quantum mechanics; liquid water; parallel algorithm; data parallel; MPI; Coulombic interaction; Ewald summation; nonuniform fast Fourier transform; FFT; FFTW; NFFT; ENUF; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : Methods for performing large-scale parallel Molecular Dynamics(MD) simulations are investigated. A perspective on the field of parallel MD simulations is given. Hardware and software aspects are characterized and the interplay between the two is briefly discussed. LÄS MER

3. 2. Combined Quantum Mechanical and Molecular Dynamics study of paramagnetic complexes : Towards an understanding of electronic spin relaxation

   Författare :Shehryar Khan; Michael Odelius; Jozef Kowalewski; Juha Vaara; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; quantum chemistry; zero-field splitting; kemisk fysik; Chemical Physics;

   Sammanfattning : The prime objectives of contrast agents in Magnetic Resonance Imaging (MRI) is to accelerate the relaxation rate of the solvent water protons in the surrounding tissue. Paramagnetic relaxation originates from dipole-dipole interactions between the nuclear spins and the fluctuating magnetic field induced by unpaired electrons. LÄS MER

4. 3. Numerical methods for quantum molecular dynamics

   Författare :Katharina Kormann; Sverker Holmgren; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The time-dependent Schrödinger equation models the quantum nature of molecular processes. Numerical simulations of these models help in understanding and predicting the outcome of chemical reactions. LÄS MER

5. 4. Combined Molecular Dynamics and Embedded-Cluster Calculations in Metal Oxide Surface Chemistry

   Författare :Björn Herschend; Kersti Hermansson; Micael Baudin; Joachim Sauer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; embedded-cluster; ab initio; molecular dynamics; metal oxide; ceria; magnesium oxide; adsorption; surface defect; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

   Sammanfattning : The development and improvement of the functionality of metal oxides in heterogeneous catalysis and other surface chemical processes can greatly benefit from an atomic-level understanding of the surface chemistry. Atomistic calculations such as quantum mechanical (QM) calculations and molecular dynamics (MD) simulations can provide highly detailed information about the atomic and electronic structure, and constitute valuable complements to experimental surface science techniques. LÄS MER

7. 5. A theoretical perspective on photoinduced reactions - based on quantum chemical models and non-adiabatic molecular dynamics

   Författare :Sambit Das; Michael Odelius; Mårten Ahlquist; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Non-adiabatic dynamics; Molecular dynamics; Surface hopping; TDDFT; X-ray absorption spectroscopy; kemisk fysik; Chemical Physics;

   Sammanfattning : The broad range of applications for photochemical reactions is the result of light-matter interaction at the electronic level. The diverse application of photochemistry in various fields, including photovoltaic materials, molecular switches, and biological systems are due to electronic and structural transformations induced by photoexcitation as well as molecular alteration due to electron and charge transfer. LÄS MER