Ten million atom multiresolution molecular-dynamics simulations are performed on parallel computers to determine atomic-level stress distributions in a 54 nm nanopixel on a 0.1 &mgr;m silicon substrate. Effects of surfaces, edges, and lattice mismatch at theSi(111)/Si3N4(0001)interface on the stress distributions are investigated. Stresses are found to be highly inhomogeneous in the nanopixel. The top surface of silicon nitride has a compressive stress of+3 GPaand the stress is tensile,−1 GPa,in silicon below the interface. ©1998 American Institute of Physics.