LAMMPS (30 Aug 2013)
units       real
atom_style  atomic
variable lattice_constant equal 5.256227487
variable c equal 4
variable L equal (${lattice_constant}*$c)
variable L equal (5.2562274870000003091*$c)
variable L equal (5.2562274870000003091*4)
# create system
lattice        fcc ${lattice_constant}
lattice        fcc 5.2562274870000003091
Lattice spacing in x,y,z = 5.25623 5.25623 5.25623
region         box block 0 $c 0 $c 0 $c
region         box block 0 4 0 $c 0 $c
region         box block 0 4 0 4 0 $c
region         box block 0 4 0 4 0 4
boundary       p p p
# the stretched configuration of the atoms
read_data read_xref_1.init
Reading data file ...
  orthogonal box = (-1.05125 -1.05125 -1.05125) to (22.0762 22.0762 22.0762)
  1 by 2 by 2 MPI processor grid
  256 atoms
  256 velocities
mass         1 39.95
pair_style lj/cut 13.5
pair_coeff 1 1 0.238 3.405
# define region
neighbor  1.0 bin
neigh_modify  delay 1000000
thermo    1
thermo_style  custom step vol etotal
timestep  0
fix         ATC all atc field Ar_CauchyBorn.mat
ATC: constructing shape function field estimate with parameter file Ar_CauchyBorn.mat
 ATC: version 2.0
 ATC: peratom PE compute created with ID: 3
# the original configuration of the atoms
fix_modify  ATC  reset_atomic_reference_positions read_xref_0.data
# "box" is the original box
fix_modify  ATC mesh create 1 1 1 box f f f
 ATC: created uniform mesh with 8 nodes, 8 unique nodes, and 1 elements
fix_modify  ATC  fields none
fix_modify  ATC  fields add mass_density
fix_modify  ATC  output read_xrefFE 1 text
 ATC: Warning : text output can create _LARGE_ files
 ATC: output custom names:

fix_modify  ATC  output index step
variable u1 atom x-f_ATC[1]
variable u2 atom y-f_ATC[2]
variable u3 atom z-f_ATC[3]
variable rho atom mass*f_ATC[4]
dump  CONFIG all custom 1 read_xref.dmp id type x y z v_u1 v_u2 v_u3 v_rho
run 1
Setting up run ...
 ATC: P0, found 256 atoms in reference file
 ATC: P0, read  256 reference positions
 ATC: CB stiffness: 7.56717 Einstein freq: 0.355649
Memory usage per processor = 16.0674 Mbytes
Step Volume TotEng 
       0    12370.307   -416.09102 
       1    12370.307   -416.09102 
Loop time of 0.00302124 on 4 procs for 1 steps with 256 atoms

Pair  time (%) = 0.000536978 (17.7734)
Neigh time (%) = 0 (0)
Comm  time (%) = 0.000412047 (13.6383)
Outpt time (%) = 0.0019865 (65.7513)
Other time (%) = 8.57115e-05 (2.83696)

Nlocal:    64 ave 64 max 64 min
Histogram: 4 0 0 0 0 0 0 0 0 0
Nghost:    1700 ave 1700 max 1700 min
Histogram: 4 0 0 0 0 0 0 0 0 0
Neighs:    7936 ave 7936 max 7936 min
Histogram: 4 0 0 0 0 0 0 0 0 0
FullNghs:  15872 ave 15872 max 15872 min
Histogram: 4 0 0 0 0 0 0 0 0 0

Total # of neighbors = 63488
Ave neighs/atom = 248
Neighbor list builds = 0
Dangerous builds = 0