Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"hybrid functionals"”.
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Hybrid density functionals with proper exact exchange
Hybrid density functionals have the best overall performance among standard density func-tional approximations (DFA). According to their original design, hybrid DFAs are supposedto use the exact exchange (EXX). However, when hybrid functionals were originally intro-duced, there was no simple method …
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Excited State Dynamics of Trans-Cis Photoisomerization in Photoactive Yellow Protein Chromophores
… 10 times faster than the conventional TDDFT with hybrid functionals without sacrificing chemical accuracy.
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An investigation into the phase stability of manganese oxide using quantum Monte Carlo and insights into materials prediction in the barium-ruthenium-sulfur phase space
… conventional density functional theory and some hybrid functionals, fixed node diffusion Monte Carlo finds the rock salt structure to be more stable than the zincblende structure, and thus recovers the correct energy ordering. Analysis of the site-resolved charge fluctuations of the wave …
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Development of more accurate computational methods within linear-scaling density functional theory
… have to be made. These approximate functionals generally describe dispersion interactions poorly. In this thesis empirical corrections for dispersion have been developed with parameters optimised for a large set of dispersion bound complexes for the onetep code. This provides a much …
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Theoretical studies on the properties and dynamics of electronic excited states
… charge-transfer excited states with semi-local functionals. Condensed phase dynamics of excited states are even more intractable on account of the computational cost scaling exponentially with the number of condensed phase particles under consideration. However, it is still possible to develop …
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Computational methods for small-molecule transparent semiconductors
… optimally tuned and screened range-separated hybrid functionals in order to compute accurate photoabsorption spectra with relatively low computational cost. Additionally, we utilize molecular graph neural networks as a means to leverage quantum mechanical datasets to accelerate the materials …
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DESCRIPTION OF POLARONS IN LAYERED TRANSITION METAL OXIDES USING THE r2SCAN DENSITY FUNCTIONAL WITH FULLY NONLOCAL CORRECTIONS AND EFFECT OF STRAIN ON THE BAND GAP OF MONOLAYER MOLYBDENUM DISULFIDE
… their properties and enhance functionality. Hybrid functionals like HSE06, though effective for describing defects, face challenges in geometry optimization for large supercells. The r2SCAN+rVV10+U+Ud method provides a computationally efficient alternative. By selecting appropriate U and Ud …
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Weak interactions and excited states from Coulomb-attenuated DFT
… Well established exchange-correlation functionals, such as the ubiquitous B3LYP, provide reasonable accuracy, but their continued use is increasingly based on the collective experience with the functional that has been accumulated, rather than the results that can be achieved. This …
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Orbital-dependent exchange-correlation functionals in density-functional theory realized by the FLAPW method
… theory (DFT), to orbital-dependent functionals for the exchange-correlation (xc) energy. In contrast to the commonly applied local-density approximation (LDA) and generalized gradient approximation (GGA) for the xc energy, orbital-dependent functionals depend directly on the …
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From Hartree Product to Kohn-Sham and Beyond: Exploring Self-Interaction in Self-Consistent Field Methods
… density functional theory (KS-DFT) approximate functionals display to varying extents. It originates from the incomplete cancellation of the Coulomb self-repulsion by the approximate exchange functionals. This is one of the major challenges for DFT, and therefore increasing our understanding of …