PNAS Plus Significance Statements Mapping the stochastic response of nanostructures

A challenge in nanotechnology is that nanoscale structures exhibit a rate-dependent and apparently random (stochastic) load-deflection behavior when repeated experimental measurements are compared. The variability in mechanical response is due to the extreme nonconvexity of the nanostructure’s energy versus structure function. The many minima of this function correspond to equilibrium states, accessible during loading, that create many possible pathways. Traditional atomistic simulation techniques cannot systematically address this complexity. Here (pp. E1678–E1686), we explore a new method based on constructing an “equilibriummap” (akin to a phase diagram) that efficiently and systematically explores a nanostructure’s stochastic, rate-dependent response to specified loading conditions. We demonstrate the method’s capabilities and its surprisingly complex results for the case of a nanoslab of nickel under uniaxial compression.