I want to create a bicrystal separated by a symmetric tilt grain boundary. In documentation, the delete_atoms command is able to remove atoms that are too close to each other.
However, it’s mentioned that when “overlap” style is used, a pair style with force cutoffs greater than or equal to the desired overlap cutoff between pairs of relevant atom types must be included, even though the pair potential will not be evaluated. I found that for the pair potential file that I use, the cutoff value (0.3 distance unit) is, I think, too small such that there are still several atoms in GB that are too close to each other. As a result, when I try to obtain a relaxed structure, most atoms near the boundary are significantly displaced, making the boundary looks amorphous. However, when I increase the cutoff value (to 1.2 distance unit) and relax the structure again, most atoms near the boundary are not displaced so much and symmetric tilt GB structure is still preserved.
My question is: what would be the physical consequence if I use the cutoff value for “overlap” style in delete_atoms command that is higher than the cutoff of the pair potential?
That concludes my email and many thanks for your help.