Hello
I want to calculate the thermal conductivity of a graphene sheet. At this moment, I have relaxed my structure, but in the code, I have implemented values for the heat in the cold and hot regions (View the values of eheat and rheat). However, I would like to know how to compute this value for my material.
INPUT SCRIPT: in.heatflux
units real
atom_style molecular
boundary p p p
processors 2 1 1
read_restart graphene.restart
neighbor 2.0 bin
neigh_modify delay 0 every 1 check yes
pair_style airebo 3.0
pair_coeff * * CH.airebo C
group carbon_atoms type 1
variable xmax equal bound(carbon_atoms,xmax)
variable xmin equal bound(carbon_atoms,xmin)
variable L equal ({xmax}-{xmin})
print “xmax: {xmax}"
print "xmin: {xmin}”
variable ymax equal bound(carbon_atoms,ymax)
variable ymin equal bound(carbon_atoms,ymin)
print “ymax: {ymax}" print "ymin: {ymin}”
variable x1 equal ({xmin}+0.25*{L})
variable x2 equal ({xmin}+0.33*{L})
variable x3 equal ({xmin}+0.67*{L})
variable x4 equal ({xmin}+0.75*{L})
print “L: {L}"
print "x1: {x1}”
print “x2: {x2}"
print "x3: {x3}”
print “x4: ${x4}”
reset_timestep 0
Thermal conductivity simulation starts from here
variable eheat equal 0.0021560
variable rheat equal -0.0021560
region hot block {x1} {x2} INF INF INF INF units box
region cold block {x3} {x4} INF INF INF INF units box
group hot region hot
group cold region cold
fix 1 hot heat 1000 v_eheat region hot
fix 2 cold heat 1000 v_rheat region cold
fix 3 all nve
compute myKE all ke/atom
compute Thot hot temp/region hot
compute Tcold cold temp/region cold
variable atemp atom c_myKE/(1.58.6217380.00001)
thermo_style custom elaplong step temp pe ke etotal press vol c_Thot c_Tcold
thermo 100
timestep 0.001
run 50000
#-----Calculation of thermal conductivity for 24ns-------------
compute temp_chunks all chunk/atom bin/1d x lower 1.0 units box
compute temp_chunks2 all chunk/atom bin/1d x lower 2.0 units box
compute temp_chunks4 all chunk/atom bin/1d x lower 4.0 units box
reset_timestep 0
fix 4a all ave/chunk 1000000 1 1000000 temp_chunks v_atemp file 1Temperature.txt ave running overwrite
fix 4b all ave/chunk 1000000 1 1000000 temp_chunks v_atemp file 1Temperature2.txt ave running overwrite
fix 5a all ave/chunk 2000000 1 2000000 temp_chunks2 v_atemp file 2Temperature.txt ave running overwrite
fix 5b all ave/chunk 2000000 1 2000000 temp_chunks2 v_atemp file 2Temperature2.txt ave running overwrite
fix 6a all ave/chunk 4000000 1 4000000 temp_chunks4 v_atemp file 4Temperature.txt ave running overwrite
fix 6b all ave/chunk 4000000 1 4000000 temp_chunks4 v_atemp file 4Temperature2.txt ave running overwrite
dump 1 all atom 1000000 dump_final.lammpstrj
run 240000
unfix 4a
unfix 4b
unfix 5a
unfix 5b
unfix 6a
unfix 6b
write_restart graphene_heatflux.restart