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Full-Text Articles in Physics
Force-Enhanced Atomic Refinement: Structural Modeling With Interatomic Forces In A Reverse Monte Carlo Approach Applied To Amorphous Si And Sio2, A. Pandey, Parthapratim Biswas, D. A. Drabold
Force-Enhanced Atomic Refinement: Structural Modeling With Interatomic Forces In A Reverse Monte Carlo Approach Applied To Amorphous Si And Sio2, A. Pandey, Parthapratim Biswas, D. A. Drabold
Faculty Publications
We introduce a structural modeling technique, called force-enhanced atomic refinement (FEAR). The technique incorporates interatomic forces in reverse Monte Carlo (RMC) simulations for structural refinement by fitting experimental diffraction data using the conventional RMC algorithm, and minimizes the total energy and forces from an interatomic potential. We illustrate the usefulness of the approach by studying a−SiO2 and a−Si. The structural and electronic properties of the FEAR models agree well with experimental neutron and x-ray diffraction data and the results obtained from previous molecular dynamics simulations of a−SiO2 and a−Si. We have shown that the method is more efficient …
Impact Of Homogeneous Strain On Uranium Vacancy Diffusion In Uranium Dioxide, Anuj Goyal, Simon R. Phillpot, Gopinath Subramanian, David A. Andersson, Chris R. Stanek, Blas P. Uberuaga
Impact Of Homogeneous Strain On Uranium Vacancy Diffusion In Uranium Dioxide, Anuj Goyal, Simon R. Phillpot, Gopinath Subramanian, David A. Andersson, Chris R. Stanek, Blas P. Uberuaga
Faculty Publications
We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect …