Incidence of atomic shuffling on the shear and decohesion behavior of a symmetric tilt grain boundary in copper F. Sansoz and J. F. Molinari Scripta Materialia, 50, 1283-1288 (2004). ABSTRACT The constitutive response of a S9(221) symmetric tilt grain boundary in copper is investigated with an atomistic quasicontinuum method under tension and shear. The maximum strength is found to change with the deformation mode triggered at the interface. Atom shuffling processes cause a major decrease in the intrinsic boundary strength under shear.