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Showing 1 to 10 of 10 for “"molecular crystal"”.
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Applications of Nuclear Quadrupole Double Resonance Spectroscopy
… quadrupolar nucleus (S (GREATERTHEQ) 1) in a molecular crystal. However, due to experimental difficulties related to the low transition frequencies generally associated with the light nuclei (D, ('10)B, ('11)B, ('14)N, and ('17)O) and, in the case of ('17)O, the low natural abundance, the …
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Computational Methodologies for the Simulation and Analysis of Low-frequency Vibrations in Molecular Crystals
… to calculate a host of physical phenomena in molecular solids ranging from mechanical elasticity to the energetic stability ordering of polymorphs. However, with the many software packages and methodologies available, it can be difficult to select the most suitable model for the problem at …
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Towards routine modelling of condensed phases with the accuracy of quantum Diffusion Monte Carlo
Molecular crystals are critical in diverse fields, including organic semiconductors, optoelectronics, medicine, and pharmaceuticals. A primary aim of computational studies in this area is to aid experimental structure determination and predict finite-temperature relative stabilities with …
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Electronic Structure Modelling of Singlet Fission in Organic Photovoltaics
… to study the excitations involved in fission in molecular crystals and dimers, using the well-studied pentacene molecule as a reference system. Linear-scaling density functional theory (LS-DFT) is used to model the influence of the crystal environment on charge-transfer (CT) configurations in the …
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Classical Hamiltonian dynamics of a particle interacting with the vibrational modes of a one-dimensional medium
"The polaron and more generally the basic problem of a particle interacting with the vibrational modes of the local medium are important to a large range of physical processes. The complex behavior and underlying properties of polaron dynamics has been the focus of much research for many years. …
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Theory of Electronic Response to Electromagnetic Fields in Crystalline Solids
… a semi-classical theory of such interactions in crystalline materials and introduce microscopic polarization and magnetization fields, and free charge and current densities, from which the macroscopic analogues can be found. We do so by identifying "sites" in an extended system with respect to …
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Energy transfer and localization in molecular crystals
… condensed-phase energetic materials via reactive molecular dynamics (MD) simulations. We characterize the response of three unique high energy density molecular crystals to different means of energy input: electric fields of various frequencies (100 − 4000<em>cm</em>−1) and strengths, and direct …
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A theoretical study of molecular crystals
… method (BIM), has been proposed for molecular clusters and molecular crystals. An infinitely extended, periodic, one-dimensional zigzag hydrogen fluoride chain was studied with this method and the energies, structures, harmonic, and anharmonic frequencies of the infrared- and/or …
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The multi Davydov-Ansatz
… we illuminate diverse aspects of laser-driven molecular dynamics in dissipative environments. Based on a rigorous investigation of the time-dependent variational principle for moving Gaussian basis functions, we systematically develop a linear algebra formulation of the system of equations of …
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Ultrafast Dynamics in Quasi-One-Dimensional Organic Molecular Crystals
Der erste Teil der Arbeit beschäftigt sich mit ultraschnellen Relaxationsprozessen in quasi-eindimensionalen organischen Molekülkristallen. Als Modellsystem wird das Perylenderivat MePTCDI untersucht. Mit verschiedenen Methoden der optischen Ultrakurzzeit-Spektroskopie werden Prozesse der …