Molecular dynamics simulations of ⟨1 0 (1)over-bar 0⟩/ψ tilt grain boundaries in ice

In this paper, molecular dynamics simulations (MDS) of < 1 0 (1) over bar 0 >/psi symmetric tilt ice grain boundaries are presented. The MDS were carried out using the GROMACS v4.5.5 program, and the water molecules were described using the TIP5P-Ew model. The grain boundary energies, gamma(gb), relative to those of the surface free energies, gamma(s), were obtained as a function of the misorientation angle psi, and compared with the gamma(gb)/gamma(s) values experimentally obtained. The results show a good correspondence between the experimental and simulated values. The planar density of coincidence sites at the grain boundary planes, Gamma, was obtained as a function of psi. The Gamma values were compared with the simulated gamma(gb)/gamma(s) values and a relation between the minimum of the simulated gamma(gb)/gamma(s) values and the maximum of the Gamma values was observed, suggesting that the CSL theory is a good starting point to detect low energy ice GBs.