# [lammps-users] Grenn-Kubo thermal conductivity

Hello Dear .
I am working on 2D materials . I want to use the Green-Kubo method to calculate thermal conductivity of a layer.we should see thermal conductivity in z direction go to zero but i have a problem with it. can anyone help me?
my input file :
fix 2 all nve/spin lattice moving
fix langevin all langevin 300 300 0.1 212
fix 1 all langevin/spin 300.0 0.01 21
run 5000000
unfix 1
unfix langevin
unfix 2
log log2
fix nve all nve/spin lattice moving
run 5000000
#!~~~~~~~~~~~~~~~~~~~~~~~~~~ Thermal Conductivity~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
log log3
reset_timestep 0
compute myKE all ke/atom
compute myPE all pe/atom
compute myStress all stress/atom NULL virial
compute flux all heat/flux myKE myPE myStress
variable Jx equal c_flux[1]/\$V
variable Jy equal c_flux[2]/\$V
variable Jz equal c_flux[3]/\$V

fix JJ all ave/correlate \$s \$p \$d &
c_flux[1] c_flux[2] c_flux[3] type auto &
file J0Jt.dat ave running

variable scale equal {convert}/{kB}/\$T/\$T/\$V*s*{dt}
variable k11 equal trap(f_JJ[3]){scale} variable k22 equal trap(f_JJ[4])*{scale}
variable k33 equal trap(f_JJ[5])
\${scale}
thermo \$d
thermo_style custom step temp v_Jx v_Jy v_Jz v_k11 v_k22 v_k33
run 100000000
variable kappa equal (v_k11+v_k22+v_k33)/3.0

output :
Step Temp v_Jx v_Jy v_Jz v_k11 v_k22 v_k33
0 310.41681 0.00097086593 -0.00035571784 0.0010384262 0.2481778 0.033316217 0.2839198
500000 302.79597 0.0006452224 0.00058312067 0.00061983717 1475.6059 3.7518179 245.78728
1000000 302.62724 0.00091829275 8.8467247e-05 -1.5794028e-05 1465.2928 2.8592287 244.84096
1500000 291.01002 0.00043891512 -0.00025512245 0.00046115919 1431.3635 2.2612376 244.87986
2000000 309.10584 0.00040328393 0.00020908168 0.00043143305 1369.6707 4.0711709 244.92324
2500000 299.47729 0.00065844799 -0.00023452236 -9.2122265e-05 1353.6262 9.3481787 245.12447
3000000 302.83536 0.0008714856 -0.00030190685 0.00052696067 1322.0514 8.9720432 245.48835
3500000 307.20157 0.00082554617 -2.8692673e-05 0.00032560403 1325.3051 7.3392584 245.27083
4000000 291.6418 0.00031994073 -5.0548848e-06 0.00021734272 1323.9348 6.4516037 244.98403
4500000 298.17572 0.00039100734 -5.8907428e-05 -0.00030403381 1287.5296 5.7105012 244.90965
5000000 309.91727 0.00078750678 0.00019214226 0.00057458791 1282.3302 5.0962099 244.75227
5500000 299.33505 0.00074718026 0.00048706747 0.00068164547 1302.3627 4.7429566 244.57132
6000000 308.66853 0.0005244758 -0.00031344634 2.6752426e-05 1310.6693 4.3571592 244.61644
6500000 294.99171 0.00084035358 8.0085464e-05 0.0002589749 1319.4035 4.3130879 244.69301
7000000 306.42204 0.0007428175 -0.00030743615 0.00026294769 1351.2133 4.8019108 244.72576
7500000 300.94026 0.00039414937 0.00027595803 0.00036238579 1354.1169 4.6362847 244.93805
8000000 297.12613 0.00074957831 0.00026721187 0.00016083295 1357.905 4.4598933 244.89021
8500000 303.70041 0.00090009248 0.00018627367 0.0007272515 1351.6712 5.1716755 244.82482
9000000 299.43973 0.00079940137 8.0699183e-05 4.4594894e-05 1335.8954 5.7895972 244.79873
9500000 298.86886 0.00034936707 -0.00017685292 0.0011460673 1343.362 5.5370847 244.76253
10000000 298.72619 0.00048314054 0.00021463264 0.00020666711 1334.5822 5.3720466 244.76235
10500000 307.4262 0.00051018736 0.00059946175 0.0002414688 1320.2362 8.0169248 244.72754
11000000 296.24854 0.00071474316 1.6789068e-05 0.00010100906 1317.3254 8.1433709 244.70513
11500000 302.50106 0.00058308983 -0.000407903 0.00063222512 1318.2123 7.70426 244.73257
12000000 299.45897 0.00027973392 4.2524571e-05 0.000122287 1309.9933 7.4425099 244.78532
12500000 298.73525 0.00080805772 0.00037286261 -8.4677791e-05 1312.6242 7.1182311 244.78679
13000000 308.48077 0.00055094997 -6.8796858e-05 0.00013446215 1319.6264 7.7322301 244.71129
13500000 314.18856 0.00075895845 4.9746451e-05 -0.00073212756 1326.0636 7.4408788 244.70673
14000000 305.54467 0.00050449949 -0.000399044 -0.00012303956 1324.7766 7.1773199 244.69392
14500000 302.62371 0.00071046857 -6.8859328e-05 0.00040783465 1317.2948 7.0492544 244.72656
15000000 310.872 0.00067434257 3.4247229e-05 0.00039550736 1317.2863 6.9716495 244.79025
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thank you very much