Figure 4.

Examples of ReaxFF applications to 2D materials. (a) Ga diffusion through a free-standing defective graphene. The graph shows a potential energy barrier for Ga diffusion into defective graphene sites: SV, DV, 5-8-5, 3 and 4 V at 0 Å. Ga diffusion realizes from right to left in the graph The images at the bottoms show the most stable Ga adsorption on SV at 1.03 Å, DV at 0 Å, 3 V at 0 Å, and 4 V model at 0 Å, respectively. Adapted with permission from ref 46. Copyright 2022 Elsevier. (b) ReaxFF and DFT predicted reaction pathway for hydrogen release from the $\text{W}{(\text{CO})}_4{\left({\text{H}}_2\text{Se}\right)}_2$ molecule. Adapted with permission from ref 43. Copyright 2019 Elsevier. (c) ADF-STEM image showing type A and B GBs, as well as the transition point between them. (d) ReaxFF MD simulation equilibrated at 300 K of the structure shown in (c). (e) Computed relative growth rate of the slanted edge structures with respect to the sulfur-terminated zigzag (ZZ) edge as a function of slanted angle, $\theta$. S(2,1), S(3,1), S(4,1), and S(6,1) are the slanted edges characterized by the translational vector (n, 1) of the 2H-${\text{WS}}_2$ lattice, where n is the number of the zigzag units along the a1 direction, and a 2-component vector contains only one zigzag unit in the GB of interest (f) Illustrations of the formation energy for adding atoms (enclosed in the dashed rectangular boxes) onto the reference sulfur terminated ZZ and S(2,1) slanted edges, respectively. Adapted with permission from ref 51. Copyright 2021 American Chemical Society. (g) Ball-stick representations and W—W bond displacement maps of V-Se and $\text{V}-{\text{Se}}_2$ point defects based on ReaxFF methods. (h) HAADF-STEM images with overlaid maps of the distances between neighboring W atoms of V-Se and $\text{V}-{\text{Se}}_2$. In (g,h) The vacancies are marked by dotted white circles. Adapted with permission from ref 44. Copyright 2020 American Chemical Society.