Four decades of classical interatomic potentials for silicon: Benchmarking thermal, defect and mechanical performance for tribology, wear and machining

Ultra-precision machining of silicon underpins semiconductor, optical and MEMS manufacturing, yet atomistic predictions remain highly sensitive to the interatomic potential employed. Here, seven popular interatomic potentials of silicon were benchmarked for thermal, cohesive, stacking-fault and tensile properties, with five carried through detailed dislocation and nanometric-cutting analyses and compared against TEM characterisation of ground silicon. The predicted responses vary markedly: apparent one-phase thermal-instability temperatures span 2309–3427 K, the unstable stacking-fault energies associated with the first {111} glide-set Shockley-partial displacement range from 1.918 to 2.948 J m −2 , and Young's moduli vary from 65.06 to 99.93 GPa. Fitted dislocation-core energies, i.e., E c (110) differ by almost a factor of six, from 0.1109 to 0.6398 eV Å −1 . These differences translate into distinct stress-accommodation pathways during cutting. ABOP (Erhart and Albe) and classical Tersoff revealed localised deformation within narrow transformed/disordered subsurface regions, Stillinger–Weber activates transient dislocation-mediated plasticity, Screened ABOP promotes extensive disorder-mediated accommodation, and Kumagai exhibits an intermediate response. TEM observations of ground silicon revealed coexisting amorphisation, {111} stacking faults and partial-dislocation activity, supporting a mixed-mechanism picture of machining-induced damage. The results show that predictive atomistic simulations of silicon machining require mechanism-specific potential selection rather than validation against a single bulk property.