Fig. 4: Twinning route of brittle metal iridium explored by the distilled-potential.

a The twinning-dominated deformation pathway in iridium proceeds via: intrinsic stacking fault (ISF) nucleation, twin nucleation, and continuous twinning propagation. b The deformation pathway in aluminum, though ultimately governed by dislocation slip, involves a transient twinning-assisted incipient stage comprising: ISF nucleation, ISF expansion, twin nucleation, multiple twinning, detwinning, and eventual transition to steady-state dislocation slip. c Variation in BCC cluster defect content with strain during nanopillar compression at 300 K, 500 K, and 800 K. d Shockley partial dislocation-mediated twinning nucleation and propagation pathway in iridium micro-pillar compression, illustrating the continuous structural evolution from perfect FCC arrangement to BCC cluster defects, to ISF, to extrinsic stacking fault (ESF), and finally to coherent twin boundary (CTB). Source data are provided as a Source Data file.