William A. Shelton

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Silicon nitride (Si3N4) ceramics are used in numerous applications because of their superior mechanical properties. Their intrinsically brittle nature is a critical issue, but can be overcome by introducing whisker-like microstructural features. However, the formation of such anisotropic grains is very sensitive to the type of cations used as the sintering(More)
MADNESS (multiresolution adaptive numerical environment for scientific simulation) is a high-level software environment for solving integral and differential equations in many dimensions that uses adaptive and fast harmonic analysis methods with guaranteed precision based on multiresolution analysis and separated representations. Underpinning the numerical(More)
First principles methods are used to aid the metallurgist in the investigation and design of new materials. However, these methods suuer from an O(N 3) scaling which restricts the problem sizes that can be addressed. By incorporating the QMR method into a rst principles algorithm we are able to attain O(N) scaling for the problem sizes of interest. This(More)
We have used the power of massively parallel computers to perform first principles spin dynamics (SD) simulations of the magnetic structure of Iron-Manganese/Cobalt (FeMn/Co) interfaces. These large scale quantum mechanical simulations, involving 2016-atom super-cell models, reveal details of the orientational configuration of the magnetic moments at the(More)
In this paper, we present experiences relating to two simulations running on a dedicated network of supercomputers that are connected and scheduled with I-WAY. Each code uses PVM as the message passing layer so that the heterogeneity of the computers becomes transparent. The rst application is a unique O(N) rst principles materials science simulation that(More)
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