I am having a curious problem using the LAMMPS cg minimizer. I have had unexpected results during the indentation of a Gold thin film that I have been investigating. The minimizer, given a block of pure Gold and using the eam potential is allowed to relax in a large vacuum. Upon completion of relaxation (which takes only 400 steps for 77k atoms), the magnitude of the residual force calculated by LAMMPS is ~10e-7. Upon inspecting the resulting atomic configuration however, I find that a region triangular in cross-section comprising one edge is warped.
I have attached the input file used.
Thanks in advance for any help.
# 3d minimization
boundary p p p
neigh_modify delay 5
# create geometry
lattice fcc 4.08 orient z 1 1 1 orient x 1 1 -2 orient y -2 2 0 origin 0 0 0
#Create simulation domain
region simblock block 0 210.0 0 210.0 0 210.0 units box
#Create region of Au material
region AuBlock block 40.8 163.2 40.8 163.2 40.8 130.56 units box
#Declare simulation box to occupy simulation domain
create_box 1 simblock
#Declare Au atoms to occupy region set aside for Au block
create_atoms 1 region AuBlock
# EAM potentials
pair_coeff * * Au_u3.eam
thermo_modify norm no
#dump dumpforce all custom 200000 conv.csp tag type x y z fx fy fz
restart 200000 conv.restart
minimize 1.0e-16 200000 200000