Computational Materials Modelling Using LAMMPS: Log file of Nickel simulation

Log file of Nickel simulation

I just wanted to show you guys how a log file looks like. As I mentioned earlier, the log file has global values(values which correspond to the entire simulation box), plays a crucial role in post-processing of data. Visit my Input and output files blog page, where I have given a brief explanation of this. Here I am going to show you the log file generated by the previous Nickel simulation. Hope this gives you an idea of how a log file looks like.

Log File

#================================================
region forbox block 0 35.2 0 35.2 0 35.2 units box
#<Refers to an abstract geometric region of space. units box refers to the fact that the size of the box is specified in the units as given in the units command. The name "forbox" refers to the region ID so that you can refer to it somewhere else in this input script.>
create_box 1 forbox #<Create the box>
Created orthogonal box = (0 0 0) to (35.2 35.2 35.2)
  1 by 1 by 1 MPI processor grid



#=======================================================================
#<Creates the lattice> <3.52 is the argument for the scale keyword, while the other a1, a2 a3 are the three lattice vectors: This is follwed by the basis commands giving the location of atoms in one unit cell.>
lattice fcc 3.52
Lattice spacing in x,y,z = 3.52 3.52 3.52
#=======================================================================
create_atoms 1 region forbox  basis 1 1 basis 2 1 basis 3 1 basis 4 1 units box
Created 4000 atoms
  create_atoms CPU = 0.0155411 secs
mass 1 58.69 #<Mass of atom type 1 is 58.69 [mass units grams/mole]>
pair_style eam
#Provide the name of the potential
pair_coeff 1 1 Ni_u3.eam
Reading potential file Ni_u3.eam with DATE: 2007-06-11
#=======================================================================
group Ni type 1 #<Group all the Nickel types (nickel type is of type 1). All atoms of type 1 are in group with the name 'Ni'
4000 atoms in group Ni
minimize 1e-25 1e-19 10000 10000 #<Minimize the energy using a conjugate gradient step.
WARNING: Using 'neigh_modify every 1 delay 0 check yes' setting during minimization (../min.cpp:168)
Neighbor list info ...
  update every 1 steps, delay 0 steps, check yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 6.8
  ghost atom cutoff = 6.8
  binsize = 3.4, bins = 11 11 11
  1 neighbor lists, perpetual/occasional/extra = 1 0 0
  (1) pair eam, perpetual
      attributes: half, newton on
      pair build: half/bin/atomonly/newton
      stencil: half/bin/3d/newton
      bin: standard
Per MPI rank memory allocation (min/avg/max) = 5.474 | 5.474 | 5.474 Mbytes
Step Temp E_pair E_mol TotEng Press
       0            0       -17800            0       -17800   -0.1203861
       2            0       -17800            0       -17800   -0.1203861
Loop time of 0.171891 on 1 procs for 2 steps with 4000 atoms

81.8% CPU use with 1 MPI tasks x 1 OpenMP threads

Minimization stats:
  Stopping criterion = energy tolerance
  Energy initial, next-to-last, final =
        -17800.0000143     -17800.0000143     -17800.0000143
  Force two-norm initial, final = 1.89504e-12 1.79872e-12
  Force max component initial, final = 4.4225e-14 4.80033e-14
  Final line search alpha, max atom move = 1 4.80033e-14
  Iterations, force evaluations = 2 4

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 0.14053    | 0.14053    | 0.14053    |   0.0 | 81.75
Neigh   | 0          | 0          | 0          |   0.0 |  0.00
Comm    | 0          | 0          | 0          |   0.0 |  0.00
Output  | 0          | 0          | 0          |   0.0 |  0.00
Modify  | 0          | 0          | 0          |   0.0 |  0.00
Other   |            | 0.03136    |            |       | 18.25

Nlocal:    4000 ave 4000 max 4000 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Nghost:    5841 ave 5841 max 5841 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Neighs:    268000 ave 268000 max 268000 min
Histogram: 1 0 0 0 0 0 0 0 0 0

Total # of neighbors = 268000
Ave neighs/atom = 67
Neighbor list builds = 0
Dangerous builds = 0
print "Finished Minimizing"
Finished Minimizing
#minimize etol ftol maxiter for minimizer maxiter for force_energy valuation
variable ener equal pe
#=========================================================
timestep  0.001
velocity all create 300 102939 dist gaussian mom yes rot yes
# Set the velocities of all the atoms so that the temperature of the system
# is 300K. Make the distribution Gaussian.
fix 1 all nve
dump dump_1 all custom 100 dump.in id type x y z ix iy iz vx vy vz #<Dump all the atoms to the file dump.in>
variable poten equal pe-${ener}
variable poten equal pe--17800.0000142793
thermo_style  custom step time temp pe ke etotal press vol v_poten
#What to print in the logfile.txt?
#=========================================================
thermo 100 #How frequently to print the thermodynamic information#
run 10000 # run with active settings as many runs as required. timestep*No. of. steps =10ps
Per MPI rank memory allocation (min/avg/max) = 4.349 | 4.349 | 4.349 Mbytes
Step Time Temp PotEng KinEng TotEng Press Volume v_poten
    2            0          300       -17800     155.0734   -17644.927    3797.6474    43614.208 1.0913936e-11
    100        0.098    168.19503   -17731.837    86.941916   -17644.895    10850.608    43614.208    68.163366
    200        0.198    138.54564   -17716.503    71.615811   -17644.887    12414.788    43614.208    83.496995
    300        0.298    140.52568   -17717.527    72.639313   -17644.888    12287.653    43614.208    82.473101
    400        0.398    148.11005    -17721.45     76.55976   -17644.891    11826.777    43614.208    78.549544
     500        0.498    150.03551   -17722.447    77.555052   -17644.892    11681.246    43614.208    77.552744
     600        0.598    150.68974   -17722.784    77.893231   -17644.891     11727.42    43614.208    77.215554
     700        0.698    151.68844   -17723.302    78.409472   -17644.892    11610.958    43614.208    76.698298
     800        0.798    142.15664   -17718.373    73.482376   -17644.891     12110.33    43614.208    81.627038
     900        0.898    146.90413   -17720.828    75.936408   -17644.892     11859.48    43614.208    79.171983
    1000        0.998    152.36031   -17723.649    78.756771   -17644.892    11574.426    43614.208    76.350935
    1100        1.098    146.35145   -17720.541    75.650721    -17644.89      11945.1    43614.208    79.459057
    1200        1.198    147.24692   -17721.005    76.113601   -17644.891    11875.792    43614.208    78.995387
    1300        1.298    150.14759   -17722.505    77.612991   -17644.892    11692.448    43614.208    77.494972
    1400        1.398     154.0402   -17724.518    79.625124   -17644.893    11490.129    43614.208    75.482013
    1500        1.498    153.95783   -17724.475    79.582544   -17644.892    11529.453    43614.208    75.525281
    1600        1.598    146.65629   -17720.698    75.808298    -17644.89    11943.606    43614.208    79.301592
    1700        1.698    149.39146   -17722.113    77.222137   -17644.891    11772.292    43614.208    77.886828
    1800        1.798    148.43346   -17721.618    76.726934   -17644.891    11819.613    43614.208     78.38204
    1900        1.898    150.56442   -17722.721    77.828454   -17644.892    11684.113    43614.208    77.279412
    2000        1.998    155.46215   -17725.253    80.360145   -17644.893    11444.123    43614.208    74.747179
    2100        2.098    153.32224   -17724.146    79.254003   -17644.892    11583.632    43614.208    75.854259
    2200        2.198    148.72913   -17721.771    76.879772   -17644.891    11793.753    43614.208      78.2292
    2300        2.298    150.38045   -17722.625    77.733357   -17644.891    11717.641    43614.208    77.375375
    2400        2.398    148.94509   -17721.883    76.991405   -17644.892    11772.397    43614.208    78.117041
    2500        2.498    148.43275   -17721.618    76.726568   -17644.891    11782.315    43614.208     78.38196
    2600        2.598    148.06121   -17721.425    76.534514   -17644.891    11834.677    43614.208    78.574861
    2700        2.698    153.42962   -17724.201    79.309506   -17644.892    11532.829    43614.208    75.798526
    2800        2.798    148.30956   -17721.554    76.662891   -17644.891    11768.555    43614.208     78.44569
    2900        2.898    152.95636   -17723.957    79.064872   -17644.892    11574.512    43614.208    76.043009
    3000        2.998    153.90203   -17724.446    79.553701   -17644.892    11533.742    43614.208    75.554119
    3100        3.098    147.78494   -17721.283    76.391709   -17644.891    11822.518    43614.208    78.716952
    3200        3.198    144.85245   -17719.767    74.875869   -17644.891    11977.807    43614.208    80.233498
    3300        3.298    149.44542   -17722.141    77.250028   -17644.891    11773.463    43614.208     77.85912
    3400        3.398    151.69406   -17723.304    78.412379   -17644.892    11618.045    43614.208    76.695781
    3500        3.498    150.03615   -17722.447    77.555387   -17644.891    11735.022    43614.208    77.553443
    3600        3.598     155.4659   -17725.254    80.362082   -17644.892    11451.688    43614.208    74.745743
    3700        3.698    153.34045   -17724.155    79.263414   -17644.892    11561.509    43614.208    75.844656
    3800        3.798    154.02334   -17724.508    79.616409   -17644.892    11525.887    43614.208    75.491626
    3900        3.898    147.89913   -17721.342    76.450736   -17644.891    11848.686    43614.208    78.658455
    4000        3.998    148.40334   -17721.602    76.711368   -17644.891    11813.499    43614.208     78.39761
    4100        4.098    149.27721   -17722.054     77.16308   -17644.891    11804.118    43614.208    77.945955
    4200        4.198    151.69124   -17723.302    78.410918   -17644.892    11645.973    43614.208    76.697521
    4300        4.298    151.99693   -17723.461    78.568932   -17644.892    11626.853    43614.208    76.539119
    4400        4.398    149.77156    -17722.31    77.418615   -17644.892    11737.948    43614.208    77.689877
    4500        4.498    149.83597   -17722.343    77.451908   -17644.891    11742.852    43614.208    77.656847
    4600        4.598    147.36143   -17721.064    76.172789   -17644.891    11850.551    43614.208    78.936153
    4700        4.698    147.40234   -17721.085    76.193937   -17644.891    11864.003    43614.208    78.915187
    4800        4.798    150.19256   -17722.528    77.636234   -17644.892    11719.793    43614.208    77.472207
    4900        4.898    150.14524   -17722.503    77.611775   -17644.892    11711.623    43614.208     77.49671
    5000        4.998    149.81174   -17722.331    77.439384   -17644.892    11706.428    43614.208    77.668992
    5100        5.098    152.03165   -17723.479    78.586879   -17644.892    11615.821    43614.208    76.521047
    5200        5.198    150.28025   -17722.573    77.681563   -17644.891    11729.935    43614.208    77.427187
    5300        5.298    149.68005   -17722.263     77.37131   -17644.891    11755.013    43614.208    77.737403
    5400        5.398    151.89276   -17723.407    78.515087   -17644.892    11617.748    43614.208    76.592725
    5500        5.498    149.14684   -17721.987    77.095691   -17644.891    11753.285    43614.208    78.012992
    5600        5.598    152.39592   -17723.667    78.775179   -17644.892    11599.311    43614.208     76.33303
    5700        5.698    151.75627   -17723.336    78.444536   -17644.891    11642.865    43614.208    76.664193
    5800        5.798    148.32024   -17721.559     76.66841   -17644.891    11810.972    43614.208     78.44063
    5900        5.898    148.49223   -17721.648    76.757313   -17644.891    11797.788    43614.208    78.352004
    6000        5.998    152.50451   -17723.723    78.831309   -17644.892    11594.098    43614.208    76.276959
    6100        6.098    154.83539   -17724.929    80.036167   -17644.892    11467.686    43614.208    75.071409
    6200        6.198    149.98052   -17722.418    77.526626   -17644.892    11697.118    43614.208    77.581639
    6300        6.298    154.82259   -17724.922    80.029547   -17644.893    11471.282    43614.208    75.077945
    6400        6.398    152.69414   -17723.821    78.929332   -17644.892    11585.236    43614.208    76.178671
    6500        6.498    151.35472   -17723.128     78.23697   -17644.891    11680.425    43614.208    76.871954
    6600        6.598    148.10481   -17721.448    76.557052   -17644.891    11820.464    43614.208    78.552187
    6700        6.698    148.68612   -17721.749    76.857541   -17644.891    11762.436    43614.208    78.251086
    6800        6.798    147.38642   -17721.077    76.185709   -17644.891    11842.966    43614.208      78.9235
    6900        6.898    150.11878    -17722.49    77.598098   -17644.891    11690.596    43614.208     77.51044
    7000        6.998    152.86574    -17723.91    79.018033   -17644.892    11551.765    43614.208    76.089993
    7100        7.098    150.60452    -17722.74    77.849182   -17644.891    11699.497    43614.208    77.259595
    7200        7.198    152.11393   -17723.521    78.629411   -17644.892    11609.588    43614.208    76.478823
    7300        7.298    146.88095   -17720.815    75.924427   -17644.891    11873.397    43614.208    79.185028
    7400        7.398    149.95607   -17722.405    77.513991   -17644.891    11717.235    43614.208    77.594959
    7500        7.498    149.57852    -17722.21    77.318829   -17644.891     11744.93    43614.208    77.790177
    7600        7.598    151.41517    -17723.16    78.268216   -17644.892    11623.682    43614.208    76.840134
    7700        7.698      151.789   -17723.353    78.461455   -17644.892    11626.981    43614.208    76.646816
    7800        7.798     150.3752   -17722.622    77.730644   -17644.891    11718.031    43614.208    77.378089
    7900        7.898    149.58652   -17722.215    77.322966   -17644.892    11724.279    43614.208    77.785508
    8000        7.998    148.44542   -17721.624    76.733121   -17644.891    11808.965    43614.208    78.376125
    8100        8.098    153.25861   -17724.113    79.221113   -17644.892    11547.918    43614.208    75.886708
    8200        8.198    151.87231   -17723.397    78.504514   -17644.892    11624.927    43614.208    76.603347
    8300        8.298    148.60851   -17721.708    76.817419   -17644.891    11816.443    43614.208    78.291905
    8400        8.398    150.12818   -17722.494    77.602957   -17644.891    11735.205    43614.208    77.506127
    8500        8.498    150.24654   -17722.555    77.664139   -17644.891     11730.75    43614.208    77.444621
    8600        8.598    150.17861   -17722.521    77.629026   -17644.892    11704.534    43614.208    77.479304
    8700        8.698    154.54424   -17724.778    79.885667   -17644.893    11468.354    43614.208    75.221572
    8800        8.798    147.79559   -17721.288    76.397211   -17644.891    11825.798    43614.208    78.711761
    8900        8.898    148.45321   -17721.628    76.737147   -17644.891    11794.686    43614.208    78.371814
    9000        8.998    152.33373   -17723.634    78.743028   -17644.891    11595.657    43614.208     76.36552
    9100        9.098    148.09314   -17721.442    76.551022   -17644.891    11818.511    43614.208    78.558448
    9200        9.198    150.03622   -17722.447    77.555418   -17644.892    11707.304    43614.208    77.553065
    9300        9.298    148.91434   -17721.867    76.975509   -17644.891    11776.772    43614.208    78.133415
    9400        9.398    150.22033   -17722.542    77.650591   -17644.891    11693.821    43614.208    77.457937
    9500        9.498    149.71583   -17722.281    77.389807   -17644.892     11709.75    43614.208    77.718623
    9600        9.598    149.44104   -17722.139    77.247763   -17644.891    11748.278    43614.208    77.861176
    9700        9.698    147.64891   -17721.212    76.321392    -17644.89    11842.637    43614.208    78.788407
    9800        9.798    148.47698    -17721.64    76.749434    -17644.89    11818.395    43614.208    78.360224
    9900        9.898      152.654   -17723.801    78.908582   -17644.892    11569.271    43614.208      76.1995
   10000        9.998    149.74646   -17722.297     77.40564   -17644.891    11714.251    43614.208    77.703031
   10002           10    149.91724   -17722.385    77.493919   -17644.891    11706.689    43614.208    77.614661
Loop time of 254.132 on 1 procs for 10000 steps with 4000 atoms

Performance: 3.400 ns/day, 7.059 hours/ns, 39.350 timesteps/s
98.3% CPU use with 1 MPI tasks x 1 OpenMP threads

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 240.43     | 240.43     | 240.43     |   0.0 | 94.61
Neigh   | 0          | 0          | 0          |   0.0 |  0.00
Comm    | 1.4389     | 1.4389     | 1.4389     |   0.0 |  0.57
Output  | 10.306     | 10.306     | 10.306     |   0.0 |  4.06
Modify  | 1.2227     | 1.2227     | 1.2227     |   0.0 |  0.48
Other   |            | 0.7346     |            |       |  0.29

Nlocal:    4000 ave 4000 max 4000 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Nghost:    5841 ave 5841 max 5841 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Neighs:    268000 ave 268000 max 268000 min
Histogram: 1 0 0 0 0 0 0 0 0 0

Total # of neighbors = 268000
Ave neighs/atom = 67
Neighbor list builds = 0
Dangerous builds = 0
undump dump_1 # Stop dumping information to the dump file.
unfix 1
# Unfix the NVE. Additional lines if any will assume that this
# fix is off.

Total wall time: 0:04:16

Explanation

If you observe log file you can see 2 sets of value. 

The first set:

Step Temp E_pair E_mol TotEng Press 
       0            0       -17800            0       -17800   -0.1203861
       2            0       -17800            0       -17800   -0.1203861

As the first line suggests, these are time step, temperature, energy and pressure value. These values correspond to energy minimisation step which I have initiated (please look at the input script in my previous post). From this, it is clear that the energy minimisation took 2-time steps. Each time step is 0.001 picoseconds or 1 femtosecond. Thus our energy minimisation process took 2 femtoseconds.

The second set:

Step Time Temp PotEng KinEng TotEng Press Volume v_poten 
    2            0          300       -17800     155.0734   -17644.927    3797.6474    43614.208 1.0913936e-11
     100        0.098    168.19503   -17731.837    86.941916   -17644.895    10850.608    43614.208    68.163366
     200        0.198    138.54564   -17716.503    71.615811   -17644.887    12414.788    43614.208    83.496995

(I am just showing 3 sets of values for explanation purpose)

As the first line suggests, these are time step, time, temperature, energy, pressure, volume values. If you notice my thermo_style command in my previous blog, I would have mentioned the exact values as command, and thus LAMMPS printed these values in our log file. These values correspond to the NVE equilibration process. The equilibration process runs for 10002 timesteps(effectively 10000 steps since the first 2 steps are of energy minimisation) because I have given 10000 timesteps in my run command. So LAMMPS stops printing values after 10002 steps. Also if you can see the values are printed for every 100 timesteps, because in my thermo_style command I have given printing frequency as 100. I have run the equilibration process for 10000 timesteps ie. 10000 femtoseconds or 10 picoseconds.

Cumulatively the entire simulation studies 10002 femtoseconds or 10.002 picoseconds. As I have mentioned earlier LAMMPS work in small timescales, which are useful in crack propagation, traditional damage studies and many phenomena which happens in a scale of picoseconds in real-time, whose experimental studies are highly expensive and difficult.

You can use this file for your post-processing like you can import your lof file to Matlab or you can copy-paste these values in an excel sheet and you can plot a graph of temperature or pressure or whatever property variation and you can study that variation. In my previous blog on Argon, I have plotted a temperature variation graph. Like this, you can study various properties.


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