variable d equal 0.8 ### DEFINE SIMULATION BOX GEOMETRY ### lattice sc ${d} region box block 0 15 0 15 0 15 create_box 1 box create_atoms 1 box ### DEFINE PHYSICAL PROPERTIES OF ATOMS ### mass 1 1.0 pair_style lj/cut/opt 3.0 pair_coeff 1 1 1.0 1.0 neighbor 2.0 bin ### SPECIFY THE REQUIRED THERMODYNAMIC STATE ### variable T equal 2.0 variable timestep equal 0.0025 ### ASSIGN ATOMIC VELOCITIES ### velocity all create ${T} 12345 dist gaussian rot yes mom yes ### SPECIFY ENSEMBLE ### timestep ${timestep} fix nve all nve ### THERMODYNAMIC OUTPUT CONTROL ### thermo_style custom time etotal temp press thermo 10 ### RECORD TRAJECTORY ### dump traj all custom 1000 output-1 id x y z ### SPECIFY TIMESTEP ### ### RUN SIMULATION TO MELT CRYSTAL ### run 10000 unfix nve reset_timestep 0 ### BRING SYSTEM TO REQUIRED STATE ### variable tdamp equal ${timestep}*100 variable ddamp equal ${timestep}*1000 fix nvt all nvt temp ${T} ${T} ${tdamp} run 10000 reset_timestep 0 ### MEASURE SYSTEM STATE ### thermo_style custom step etotal temp press density variable dens equal density variable dens2 equal density*density variable temp equal temp variable temp2 equal temp*temp variable etot equal etotal variable etot2 equal etotal*etotal fix aves all ave/time 100 1000 100000 v_dens v_temp v_etot v_dens2 v_temp2 v_etot2 run 100000 variable avedens equal f_aves[1] variable avetemp equal f_aves[2] variable aveetot equal f_aves[3] variable errdens equal sqrt(f_aves[4]-f_aves[1]*f_aves[1]) variable erretot equal sqrt(f_aves[6]-f_aves[3]*f_aves[3]) print "Averages" print "--------" print "Density: ${avedens}" print "Temperature: ${avetemp}" print "Etotal: ${aveetot}" print "erretotal: ${erretot}"