Whalen, Stephen2024-01-052024-01-052023-08https://hdl.handle.net/11299/259672University of Minnesota Ph.D. dissertation. August 2023. Major: Scientific Computation. Advisor: Ellad Tadmor. 1 computer file (PDF); viii, 101 pages.Multiscale methods allow for computer simulations of materials at larger scales, finer detail, and higher speed than traditional simulations can offer. The quasicontinuum method (QC) is a multiscale method, combining atomistic and continuum models with a sharp interface between regions. We present QC3D, a complete three-dimentional implementation of QC for multilattice materials. QC3D uses hybrid parallelization to run efficiently on shared-memory and distributed-memory computing systems, scaling to thousands of compute cores. Two example applications demonstrate QC3D’s effectiveness in correctly capturing material responses to deformation, in less compute time than fully atomistic simulators require.enDomain decompositionHigh performance computingMassively parallel processingMultiscale methodsNanostructuresThesis or Dissertation