I am intended to make a cavity in a epoxy matrix which is modeled as (FENE chain and LJ pair). When I add the indent to my input file, and the cavity with an initial r=0.1 begin to expend. However, when it come to 120 steps, it show the error as following. My idea is that bond error is caused by the large k= (force/distance^2 units) or small time step (k=1000 and t=0.012 in my simulation). After replacing a smaller k and time step, the error still exists.
Any suggestions on this problem?