# This test compares Hardy and Cauchy-Born metrics of energy density and stress
# for an Ar system undergoing dynamics at a finite temperature.
echo both
log            ftcb_constV.log  
units          real
atom_style     atomic
variable       lattice_constant equal 5.256227487 
variable       c equal 6
variable       L equal (${lattice_constant}*$c)
variable       V equal $L*$L*$L
print          "Volume : $V"
variable       Ti equal 0.0001 
variable       dT equal 0.2
variable       n equal 10000
variable       m equal 200
variable       dt equal 0.1
# create system
lattice        fcc ${lattice_constant} 
region         box block 0 $c 0 $c 0 $c
boundary       p p p
pair_style     lj/cut 13.5  
read_data      ftcb_constV_setup.init
mass           1 39.95
pair_coeff     1 1 0.238 3.405 
# define region
neighbor       1.0 bin
neigh_modify   delay 0 every 2000 check no
reset_timestep 0
thermo         $m
compute_modify thermo_temp extra 0
variable       nrepeat equal $n/$m 
variable       sxx equal -pxx
variable       intenergy equal etotal
fix            TDAVE all ave/time $m ${nrepeat} $n c_thermo_temp v_sxx v_intenergy ave one file ftcb_constV.profile
thermo_style   custom step temp press etotal lx ly lz
timestep       ${dt}
# filtered
fix            ATCFILT all atc field Ar_CauchyBorn.mat
#fix_modify     ATCFILT  reset_atomic_reference_positions ftcb_constV_setup.data
fix_modify     ATCFILT mesh create 1 1 1 box p p p 
fix_modify     ATCFILT  fields none
fix_modify     ATCFILT  fields add internal_energy stress cauchy_born_energy cauchy_born_stress
fix_modify     ATCFILT  fields add temperature displacement
fix_modify     ATCFILT  gradients add displacement
fix_modify     ATCFILT  output ftcb_constV_filteredFE $n text binary tensor_components
fix_modify     ATCFILT  sample_frequency $m
variable       scale equal $n*${dt}
fix_modify     ATCFILT  filter scale ${scale}
fix_modify     ATCFILT  filter on
fix_modify     ATCFILT  filter type step
# not filtered
fix            ATC all atc field Ar_CauchyBorn.mat
#fix_modify     ATC  reset_atomic_reference_positions ftcb_constV_setup.data
fix_modify     ATC mesh create 1 1 1 box p p p 
fix_modify     ATC  fields none
fix_modify     ATC  fields add internal_energy stress cauchy_born_energy cauchy_born_stress
fix_modify     ATC  fields add temperature displacement
fix_modify     ATC  gradients add displacement
fix_modify     ATC  output ftcb_constVFE $m text binary tensor_components
velocity       all create ${Ti} 102486 mom yes rot yes dist gaussian
# step iu T,V space
variable i loop 1 
label loop_i
  print ">>> step $i, T: ${Ti}, V: $V"
  variable Tf equal ${Ti}+${dT}
  fix NVT all nvt temp ${Ti} ${Tf} 20 drag 0.5 tchain 1
  run  $n
  unfix NVT
  fix NVT all nvt temp ${Tf} ${Tf} 20 drag 0.5 tchain 1
  run  $n
  unfix NVT
  variable Ti equal ${Tf} 
next i
jump in.ftcb_constV loop_i