When I use minimize command without specifying ftol like minimize 1.0e-4 100 1000 it seems to be working fine in that it minimizes energy from o(e8) to o(e2) , but when I include ftol as well like
minimize 1.0e-4 1.0e-6 100 1000 or minimize 0.0001 0.00001 100 1000, it says "illegal minimize command"
What version of LAMMPS is this?