# This is a test for reading an atomic reference configuration
echo both
units       real
atom_style  atomic
variable lattice_constant equal 5.256227487 
variable c equal 4
variable L equal (${lattice_constant}*$c)
# create system
lattice        fcc ${lattice_constant} 
region         box block 0 $c 0 $c 0 $c
boundary       p p p
# the stretched configuration of the atoms
read_data read_xref_1.init
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
# 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 
fix_modify  ATC  fields none
fix_modify  ATC  fields add mass_density
fix_modify  ATC  output read_xrefFE 1 text
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