Atomic link between the structure and strength of grain boundaries subject to shear coupling

Disconnection nucleation governs the incipient plasticity and strength of grain boundaries (GBs) that are subject to shear coupling. Here we report a link between the structure and critical shear stress for disconnection nucleation in a GB via atomic slip that is predictive based on the dichromatic pattern. A transition in shear strength and its dependence on tension/compression in a series of [0 0 1] symmetric tilt GBs in Cu at 0 K found from atomistic simulations perfectly match the predictions from the atomic slip analysis.