Subgrain boundary energy in Ih ice: A molecular dynamics study using mW and Tip4p/ice potentials

In this work, molecular dynamics simulations were used to calculate the energies of subgrain boundaries in ice Ih bicrystals. Based on the wurtzite structure, a series of symmetric tilt-type bicrystals with a rotation axis of ⟨011̄0⟩ were constructed for misorientations less than 20°. The subgrain boundaries were formed as an arrangement of edge dislocations, taking into account the glide set of basal slip planes to achieve the lowest energy initial configuration. The LAMMPS code was used for the simulations, testing the mW and Tip4p/Ice potentials. The energies were calculated at a temperature of 5 K, taking into account their exponential dependence on the distance perpendicular to the subgrain boundary. The resulting energies fit the Read-Shockley model for the two potentials analyzed, and both their values and those of the elastic constants derived from them agree with those obtained in previous research.