The Atomistic-to-Continuum software package (AtC), developed by Sandia National Laboratories, couples the modeling techniques of Molecular Dynamics and Finite Element Analysis in order to simulate a wide variety of complex nanoscalesystems. Our goal was to increase the parallel performance of AtC, thereby making larger simulations more computationally feasible in multicore environments. To this end, we designed and implemented parallel matrix multiplication algorithms and distributed Finite Element data and calculations across processors more intelligently.