2013-09-13 05:11:37 +08:00
|
|
|
# sample LAMMPS input script for thermal conductivity of liquid LJ
|
2013-09-13 02:30:39 +08:00
|
|
|
# thermostatting 2 regions via fix langevin
|
|
|
|
|
|
|
|
|
|
# settings
|
|
|
|
|
|
|
|
|
|
variable x equal 10
|
|
|
|
|
variable y equal 10
|
|
|
|
|
variable z equal 20
|
|
|
|
|
|
|
|
|
|
variable rho equal 0.6
|
|
|
|
|
variable t equal 1.35
|
|
|
|
|
variable rc equal 2.5
|
|
|
|
|
variable tlo equal 1.0
|
|
|
|
|
variable thi equal 1.70
|
|
|
|
|
|
|
|
|
|
#variable rho equal 0.85
|
|
|
|
|
#variable t equal 0.7
|
|
|
|
|
#variable rc equal 3.0
|
|
|
|
|
#variable tlo equal 0.3
|
|
|
|
|
#variable thi equal 1.0
|
|
|
|
|
|
|
|
|
|
# setup problem
|
|
|
|
|
|
|
|
|
|
units lj
|
|
|
|
|
atom_style atomic
|
|
|
|
|
|
|
|
|
|
lattice fcc ${rho}
|
|
|
|
|
region box block 0 $x 0 $y 0 $z
|
|
|
|
|
create_box 1 box
|
|
|
|
|
create_atoms 1 box
|
|
|
|
|
mass 1 1.0
|
|
|
|
|
|
|
|
|
|
velocity all create $t 87287
|
|
|
|
|
|
|
|
|
|
pair_style lj/cut ${rc}
|
|
|
|
|
pair_coeff 1 1 1.0 1.0
|
|
|
|
|
|
|
|
|
|
neighbor 0.3 bin
|
|
|
|
|
neigh_modify delay 0 every 1
|
|
|
|
|
|
|
|
|
|
# heat layers
|
|
|
|
|
|
|
|
|
|
region hot block INF INF INF INF 0 1
|
|
|
|
|
region cold block INF INF INF INF 10 11
|
|
|
|
|
compute Thot all temp/region hot
|
|
|
|
|
compute Tcold all temp/region cold
|
|
|
|
|
|
|
|
|
|
# 1st equilibration run
|
|
|
|
|
|
|
|
|
|
fix 1 all nvt temp $t $t 0.5
|
|
|
|
|
thermo 100
|
|
|
|
|
run 1000
|
|
|
|
|
|
|
|
|
|
velocity all scale $t
|
|
|
|
|
|
|
|
|
|
unfix 1
|
|
|
|
|
|
|
|
|
|
# 2nd equilibration run
|
|
|
|
|
|
|
|
|
|
fix 1 all nve
|
|
|
|
|
fix hot all langevin ${thi} ${thi} 1.0 59804 tally yes
|
|
|
|
|
fix cold all langevin ${tlo} ${tlo} 1.0 287859 tally yes
|
|
|
|
|
fix_modify hot temp Thot
|
|
|
|
|
fix_modify cold temp Tcold
|
|
|
|
|
|
|
|
|
|
variable tdiff equal c_Thot-c_Tcold
|
|
|
|
|
thermo_style custom step temp c_Thot c_Tcold f_hot f_cold v_tdiff
|
|
|
|
|
thermo 1000
|
|
|
|
|
run 10000
|
|
|
|
|
|
|
|
|
|
# thermal conductivity calculation
|
|
|
|
|
# reset langevin thermostats to zero energy accumulation
|
|
|
|
|
|
|
|
|
|
compute ke all ke/atom
|
|
|
|
|
variable temp atom c_ke/1.5
|
|
|
|
|
|
|
|
|
|
fix hot all langevin ${thi} ${thi} 1.0 59804 tally yes
|
|
|
|
|
fix cold all langevin ${tlo} ${tlo} 1.0 287859 tally yes
|
|
|
|
|
fix_modify hot temp Thot
|
|
|
|
|
fix_modify cold temp Tcold
|
|
|
|
|
|
|
|
|
|
fix ave all ave/time 10 100 1000 v_tdiff ave running
|
|
|
|
|
thermo_style custom step temp c_Thot c_Tcold f_hot f_cold v_tdiff f_ave
|
|
|
|
|
|
|
|
|
|
fix 2 all ave/spatial 10 100 1000 z lower 0.05 v_temp &
|
|
|
|
|
file profile.langevin units reduced
|
|
|
|
|
|
|
|
|
|
run 20000
|
