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Full-Text Articles in Engineering Science and Materials
Studies On Atomic And Molecular Properties Using Locally Scaled And Perdew-Zunger Self-Interaction Corrected Density Functional Approximations, Philip Adeniyi Oyedele
Studies On Atomic And Molecular Properties Using Locally Scaled And Perdew-Zunger Self-Interaction Corrected Density Functional Approximations, Philip Adeniyi Oyedele
Open Access Theses & Dissertations
This thesis examines some properties of atoms and molecules using one-electron self-interaction-correction (SIC) methods such as the Perdew-Zunger SIC (PZSIC) and the locally scaled SIC method of Zope and coworkers within the Fermi-Lowdin SIC formal- ism. The accuracy of electron density is examined by comparing moments of the den- sity, ⟨r^n⟩ = ∫ ρ(r)rndτ = ∫ ∞ 0 4πr2ρ(r)rndr (n = −2, −1, 0, 1, 2, 3) with the corresponding available values from the Coupled cluster (CC) singles, doubles, and perturbative triples (CCSD(T)) method. Three test sets are considered: boron through neon neutral atoms, two and four electron cations, and …
First-Principles Studies Of Structure-Property Relationships: Enabling Design Of Functional Materials, Qunfei Zhou
First-Principles Studies Of Structure-Property Relationships: Enabling Design Of Functional Materials, Qunfei Zhou
Theses and Dissertations--Chemical and Materials Engineering
First-principles calculations based on quantum mechanics have been proved to be powerful for accurately regenerating experimental results, uncovering underlying myths of experimental phenomena, and accelerating the design of innovative materials. This work has been motivated by the demand to design next-generation thermionic emitting cathodes and techniques to allow for synthesis of photo-responsive polymers on complex surfaces with controlled thickness and patterns. For Os-coated tungsten thermionic dispenser cathodes, we used first-principles methods to explore the bulk and surface properties of W-Os alloys in order to explain the previously observed experimental phenomena that thermionic emission varies significantly with W-Os alloy composition. Meanwhile, …
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.