[lammps-users] [Puzzle] Bug or Wrong invoking of create_atoms commands?

Hi,

When cutting single-crystalline along [111] direction using create_box and create_atoms commands, the pressures along [-1-12] and [1-10] directions are sufficiently large (positive), while pressures along another direciton is negtive. The desired values should be close to (although no equal to) 0, due to numerical error and the poor accuracy of the fitted potential. So I wander if my script code is wrong, or there are some intrinsic bugs in the two commands for high indices?

The sample code is like:

variable f index cry_111
log $f.log
variable freq equal 200

units metal
dimension 3
newton on
boundary p p p
atom_style atomic

lattice fcc 3.615 orient x -1 -1 2 orient y 1 -1 0 orient z 1 1 1
region box block 0 5 0 5 0 5 units lattice
region atoms block 0 5 0 5 0 5 units lattice

create_box 1 box
create_atoms 1 region atoms

pair_style eam/alloy
pair_coeff * * Cu01.eam.alloy Cu

neighbor 0.5 bin
neigh_modify delay 10

thermo_style custom step temp pe pxx pyy pzz ly lz lx
dump 1 all xyz ${freq} $f.xyz
timestep 0.001
min_style cg

minimize 1.0e-9 1.0e-9 1000 10000

The undesired results is just like:

Step Temp PotEng Pxx Pyy Pzz Ly Lz Lx
0 0 -5887.3417 90217.31 314294.21 -8266.3736 25.56191 31.306818 29.516351
171 0 -6877.9864 -30860.054 2007.9125 -3300.4238 25.56191 31.306818 29.516351
Loop time of 3.39306 on 1 procs for 171 steps with 1959 atoms

Buy the way, there are no similar problems for crystalline with only low indices such as [110] and [100].

Thanks!