I would like to know the forces for an indentation problem. The documentation says that while using the fix indent command, a 3-vector of the forces on the indenter is produced, and a scalar for the energy of interaction. I would have 2 questions about it:
I read that the energy is simply the sum of the interactions atom/indenter potential. Now what about the forces? I am pretty curious about the way it is calculated. Is the indenter assimilated as a “real” physical object on which the atoms are pushing?
I have some difficulties to print this vector. I can get the scalar for the interaction energy, but the components of the vector remain 0, which doesn’t make sense to me. I am running a relaxation process around the indenter, and here are the command I’ve been using:
fix ball all indent 10 sphere 0.0 0.0 -40 10.0 units box
fix_modify ball energy yes
thermo_style custom step f_ball f_ball f_ball f_ball
minimize 1.0e-12 20000 500000
Thanks a lot.