First-principles investigations of hydrogen trapping in YO and the YO|bcc Fe interface.

Based on first-principles calculations, the binding energy of hydrogen atom to YO and YO|bcc Fe interface (relative to bcc Fe side) with cube-on-cube orientation is at least 0.45 eV, if hydrogen substitutional is considered, or at least 0.26 eV if only hydrogen interstitial is considered.

First-principles study of the structure and band structure of Ga2Se3.

Our first-principles calculations show that the ordering of stoichiometric cation vacancies in Ga2Se3 has a large influence on the bandgap, up to 0.55 eV. Therein, the zigzag-line vacancy-ordered Ga2Se3 has the maximum bandgap (∼2.

First-principles study of bubble nucleation and growth behaviors in α U-Zr.

Bubble nucleation and growth is responsible for swelling in metallic fuels such as U-Zr. Computational modeling is useful for understanding and ultimately developing mitigation strategies for the swelling behavior of the fuel. However, the relevant fundamental parameters are not currently available.

First-principles study of diffusion of interstitial and vacancy in α U-Zr.

Metallic uranium-zirconium alloys are of interest for a variety of fast reactor designs, and there is substantial experience with the behavior of metallic fuels. Yet, there remain a number of questions regarding the mechanisms controlling fission-gas-driven swelling in these alloys. Here we present results of ab initio calculations of the diffusion behavior of interstitial and vacancy point defects in α U-Zr alloys.

First-principles study of diffusion of Li, Na, K and Ag in ZnO.

Based on ab initio total energy calculations, Li, Na and Ag interstitials are found to be stable with at least a 1.56 eV energy barrier to transform to a zinc substitutional site in ZnO, whereas K interstitial has a relatively small energy barrier at 0.79 eV.

First-principles study of diffusion of oxygen vacancies and interstitials in ZnO.

A comprehensive investigation of oxygen vacancy and interstitial diffusion in ZnO has been performed using ab initio total energy calculations with both the local density approximation (LDA) and the generalized gradient approximation (GGA). Based on our calculation results, oxygen octahedral interstitials are fast diffusers, contributing to annealing processes, as well as being responsible for the self-diffusion of oxygen for n-type ZnO, and oxygen vacancies are responsible for the self-diffusion of oxygen for p-type ZnO.