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Full-Text Articles in Physics
Effect Of Self-Interaction Correction On Molecular Polarizabilities And Core Ionization Energies, Sharmin Akter
Effect Of Self-Interaction Correction On Molecular Polarizabilities And Core Ionization Energies, Sharmin Akter
Open Access Theses & Dissertations
Density Functional Theory (DFT) is one of the most successful and popular computational Quantum Mechanical approaches to understanding materials. DFT allows the prediction of material properties from the electron density. Although in principle, density functional theory is exact, it, however, relies on approximate functional for exchange-correlation energy. Due to the approximate nature of the exchange-correlation functional, the self-Coulomb energy of the electrons is not exactly canceled out by the self-exchange, leading to the spurious self-interaction error (SIE). Due to this error, the potential shows incorrect behavior which leads to errors in calculated properties such as ionization energies, electron affinities, polarizabilities, …
A Dft Analysis And Simple Hamiltonian Modeling Of A Molecular System Employed For Experimental Evidence Of Quantum Teleportation, Pedro Ulises Medina Gonzalez
A Dft Analysis And Simple Hamiltonian Modeling Of A Molecular System Employed For Experimental Evidence Of Quantum Teleportation, Pedro Ulises Medina Gonzalez
Open Access Theses & Dissertations
Radical ion pairs (RIPs) have been used to demonstrate quantum teleportation in molecular systems for applications in quantum information science. Covalent organic donor-acceptor (D-A) molecules can produce RIPs through photo-induced charge transfer and an additional radical (R) molecule makes quantum teleportation possible. We present the electronic structure and analyze charge transfer excited states of a recently studied [1] D-A-R molecular system using density functional theory. The distances between donor-acceptor and donor-radical are about 12.9 \AA $\,$ and 21.9 \AA, respectively. The excitation energies are calculated using the perturbative delta-SCF method and agree with other conventional excited-state methods and experimental reference …
Density Functional Theory Study Of Dopant Incorporation Into Gamma-Uo3, Nicholas James Wilson
Density Functional Theory Study Of Dopant Incorporation Into Gamma-Uo3, Nicholas James Wilson
Open Access Theses & Dissertations
Uranium trioxide (UO3) is a stable uranium oxide found throughout the nuclear fuel cycle. The γ-UO3 phase is of particular interest as the most stable at ambient conditions. As such, the γ-UO3 structure was selected for a theoretical investigation into the incorporation of metal dopants for nuclear intentional forensics applications. The two lattice types of this phase, tetragonal (I41/amd) and orthorhombic (Fddd), were investigated and found to be energetically identical, and as such the smaller tetragonal structure was selected for doping. Three transition metal dopants (Cr, Fe, and Ni) were incorporated into the structure interstitially and substitutionally at a total …
Development Of Multi-Configuration Methods On Density Functional Theory Orbitals And Application On The Study Of Dimers, Jose Gustavo Bravo Flores
Development Of Multi-Configuration Methods On Density Functional Theory Orbitals And Application On The Study Of Dimers, Jose Gustavo Bravo Flores
Open Access Theses & Dissertations
The configuration interaction (CI) methods is an exact method to solve the non relativistic Schrodinger equation, describing the wave function as a linear combination of Slater determinants. Because the computation time grows factorially as the number of electrons, CI is mostly used for relatively small systems. Density functional theory (DFT) rose as one of the most used methods for computational quantum chemistry in the last 30 years. DFT can describe a system's properties with the electron density, which only depends of of three coordinates. Due to its low computational costs it allows one to study bigger systems than CI, however …
Application Of Flo-Sic To F-Electron Systems: Sixth Row Elements And Ligated Molecules, Alexander Irun Johnson
Application Of Flo-Sic To F-Electron Systems: Sixth Row Elements And Ligated Molecules, Alexander Irun Johnson
Open Access Theses & Dissertations
Density functional theory - the most widely used theoretical method to study atoms,molecules, and solids - suffers from the well-known self-interaction error. A solution to the problem was suggested by Perdew and Zunger [1], who showed the self-interaction error can be removed with self-interaction correction. In 2014, Pederson showed a unitary transformation can be performed on the Kohn-Sham orbitals to generate Fermi-Löwdin orbitals which improve atomization energies, and avoid the computational costs of solving the localization equations.[2] This method is known as the Fermi-Löwdin Orbital Self-Interaction Correction (FLO-SIC). Until now, the FLO-SIC methodology has been used for atoms not containing …
An Ab-Initio Study Of The Elastic Properties Of Important Group Iv Diborides At High Temperatures, Manny Gonzales
An Ab-Initio Study Of The Elastic Properties Of Important Group Iv Diborides At High Temperatures, Manny Gonzales
Open Access Theses & Dissertations
Presented is an ab-initio Molecular Dynamics (MD) study, employing the Density Functional Theory (DFT), of the lattice parameter, thermal expansion coefficients and elastic constants of ZrB2, TiB2 and HfB2 as a function of temperature. The MD trajectories provide the equilibrium lattice parameters at finite temperatures, and the gradient of the energy from these equilibrium solutions is then used to calculate the components of the stiffness tensor. The results for ZrB2 are shown to agree well with reported experimental results for the lattice parameters and elastic constants as a function of temperature.