78 lines
1.9 KiB
Plaintext
78 lines
1.9 KiB
Plaintext
# sample LAMMPS input script for thermal conductivity of liquid LJ
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# Muller-Plathe method via fix thermal_conductivity
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# settings
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variable x equal 10
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variable y equal 10
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variable z equal 20
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variable rho equal 0.6
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variable t equal 1.35
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variable rc equal 2.5
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#variable rho equal 0.85
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#variable t equal 0.7
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#variable rc equal 3.0
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# setup problem
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units lj
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atom_style atomic
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lattice fcc ${rho}
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region box block 0 $x 0 $y 0 $z
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create_box 1 box
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create_atoms 1 box
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mass 1 1.0
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velocity all create $t 87287
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pair_style lj/cut ${rc}
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pair_coeff 1 1 1.0 1.0
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neighbor 0.3 bin
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neigh_modify delay 0 every 1
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# 1st equilibration run
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fix 1 all nvt temp $t $t 0.5
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thermo 100
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run 1000
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velocity all scale $t
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unfix 1
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# 2nd equilibration run
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compute ke all ke/atom
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variable temp atom c_ke/1.5
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fix 1 all nve
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compute layers all chunk/atom bin/1d z lower 0.05 units reduced
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fix 2 all ave/chunk 10 100 1000 layers v_temp file profile.mp
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fix 3 all thermal/conductivity 10 z 20
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variable tdiff equal f_2[11][3]-f_2[1][3]
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thermo_style custom step temp epair etotal f_3 v_tdiff
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thermo_modify colname f_3 E_delta colname v_tdiff dTemp_step
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thermo 1000
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run 20000
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# thermal conductivity calculation
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# reset fix thermal/conductivity to zero energy accumulation
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fix 3 all thermal/conductivity 10 z 20
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variable start_time equal time
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variable kappa equal (f_3/(time-${start_time})/(lx*ly)/2.0)*(lz/2.0)/f_ave
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fix ave all ave/time 1 1 1000 v_tdiff ave running
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thermo_style custom step temp epair etotal f_3 v_tdiff f_ave
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thermo_modify colname f_3 E_delta colname v_tdiff dTemp_step colname f_ave dTemp
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run 20000
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print "Running average thermal conductivity: $(v_kappa:%.2f)"
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