Silicon compression test

I have an error during equlibration : ERROR: Lost atoms: original 1530 current 1466 (../thermo.cpp:392)
Dont know what is the reason and how to solve the problem. Also how to know the centro/atom for silicon! Thanks
Mohamed

# ------------------------ INITIALIZATION ----------------------------
units metal
dimension 3
boundary p p p
atom_style atomic

# ----------------------- ATOM DEFINITION ----------------------------
variable latparam equal 5.43
region whole block 0 30 0 30 0 30
create_box 1 whole
lattice diamond ${latparam} orient x 1 0 0 orient y 0 1 0 orient z 0 0 1
mass 1 28.0855
create_atoms 1 region whole
replicate 1 1 1

# ------------------------ FORCE FIELDS ------------------------------
pair_style sw
pair_coeff * * si.sw Si

neighbor 2.0 bin
neigh_modify delay 0 every 10 check yes

# ------------------------- SETTINGS ---------------------------------
compute csym all centro/atom 4
compute eng all pe/atom

I have an error during equlibration : ERROR: Lost atoms: original 1530 current 1466 (../thermo.cpp:392)
Dont know what is the reason and how to solve the problem.

try looking here: http://lmgtfy.com/?q=lost+atoms+lammps

Also how to know the centro/atom for silicon! Thanks

try looking here: http://lammps.sandia.gov/doc/compute_centro_atom.html