[lammps-users] puzzle about indent simulation

Hi steve:
I modified the in file according to your advice(fix all nve &don’t fix rigid),and it works!all the problems are solved, but I don’t kown why these changes lead to this result? So, if it doesn’t cost you much time, would you please explain the reason?
Thanks !

Fix rigid is complicated, so I don't use it unless it's needed. In general
a rigid body can rotate, even if it's center-of-mass velocity is constant,
so apparantly yours did. There are fix rigid options to turn off torque (hence
no rotation), but again it's more complicated than you need for what you
want to do.