LAMMPS (18 Feb 2013)
# 2d friction simulation

dimension	2
boundary	p s p

atom_style	atomic
neighbor	0.3 bin
neigh_modify	delay 5

# create geometry

lattice		hex 0.9
Lattice spacing in x,y,z = 1.1327 1.96189 1.1327
region		box block 0 50 0 22 -0.25 0.25
create_box	4 box
Created orthogonal box = (0 0 -0.283174) to (56.6348 43.1615 0.283174)
  1 by 1 by 1 MPI processor grid

mass		1 1.0
mass		2 1.0
mass		3 1.0
mass		4 1.0

# atom regions

region          lo-fixed block INF INF INF 1.1 INF INF
region          lo-slab block INF INF INF 7 INF INF
region          above-lo block INF INF INF 7 INF INF side out
region          hi-fixed block INF INF 20.9 INF INF INF
region          hi-slab block INF INF 15 INF INF INF
region          below-hi block INF INF 15 INF INF INF side out
region		lo-asperity sphere 32 7 0 8
region		hi-asperity sphere 18 15 0 8
region		lo-half-sphere intersect 2 lo-asperity above-lo
region		hi-half-sphere intersect 2 hi-asperity below-hi

# create 2 surfaces with asperities

create_atoms	1 region lo-slab
Created 750 atoms
create_atoms	1 region hi-slab
Created 750 atoms
create_atoms	2 region lo-half-sphere
Created 112 atoms
create_atoms	3 region hi-half-sphere
Created 112 atoms

# LJ potentials

pair_style	lj/cut 2.5
pair_coeff	* * 1.0 1.0 2.5

# define groups

group	        lo region lo-slab
750 atoms in group lo
group		lo type 2
862 atoms in group lo
group		hi region hi-slab
750 atoms in group hi
group		hi type 3
862 atoms in group hi
group		lo-fixed region lo-fixed
150 atoms in group lo-fixed
group		hi-fixed region hi-fixed
150 atoms in group hi-fixed
group		boundary union lo-fixed hi-fixed
300 atoms in group boundary
group		mobile subtract all boundary
1424 atoms in group mobile

set		group lo-fixed type 4
  150 settings made for type
set		group hi-fixed type 4
  150 settings made for type

# initial velocities

compute         new mobile temp/partial 0 1 0
velocity	mobile create 0.1 482748 temp new
velocity	hi set 1.0 0.0 0.0 sum yes

# fixes

fix		1 all nve
fix		2 boundary setforce 0.0 0.0 0.0
fix		3 mobile temp/rescale 200 0.1 0.1 0.02 1.0
fix_modify	3 temp new

# Run

timestep	0.0025
thermo		1000
thermo_modify	temp new
WARNING: Temperature for thermo pressure is not for group all (thermo.cpp:436)

#dump		1 all atom 500 dump.friction

#dump		1 all image 500 image.*.jpg type type #		zoom 1.6 adiam 1.5
#dump_modify	1 pad 5

run		20000
Memory usage per processor = 2.06912 Mbytes
Step Temp E_pair E_mol TotEng Press Volume 
       0          0.1   -3.1333672            0   -3.0921259   -1.1437867    2444.9333 
    1000          0.1   -3.0915465            0   -3.0503052  0.010015559    2444.9333 
    2000          0.1   -3.0826487            0   -3.0414074  -0.42012889    2444.9333 
    3000  0.089819692     -3.07584            0   -3.0387972  -0.25252108    2444.9333 
    4000  0.098489874   -3.0667093            0   -3.0260907  -0.25506538    2444.9333 
    5000   0.11379986   -3.0557087            0   -3.0087762 -0.080871179    2444.9333 
    6000   0.11269179     -3.04532            0   -2.9988445  -0.33381202    2444.9333 
    7000          0.1   -3.0380598            0   -2.9968185  -0.32423909    2444.9333 
    8000          0.1   -3.0346453            0    -2.993404  -0.38015347    2444.9333 
    9000          0.1   -3.0324305            0   -2.9911892  -0.42940009    2444.9333 
   10000   0.11811429   -3.0334969            0    -2.984785  -0.32538147    2444.9333 
   11000   0.11627653   -3.0344827            0   -2.9865288  -0.45037424    2444.9333 
   12000   0.11250787   -3.0472157            0    -3.000816  -0.27347069    2444.9333 
   13000   0.11429889   -3.0455404            0   -2.9984021  -0.28832736    2444.9333 
   14000   0.11292741   -3.0466673            0   -3.0000946  -0.38939496    2444.9333 
   15000   0.11239299   -3.0460428            0   -2.9996905  -0.35437935    2444.9333 
   16000   0.11775554   -3.0457709            0    -2.997207  -0.14263984    2444.9333 
   17000   0.11456908   -3.0459128            0    -2.998663   -0.3686153    2444.9333 
   18000    0.1165453   -3.0454305            0   -2.9973657   -0.3572725    2444.9333 
   19000   0.11403056   -3.0440495            0   -2.9970218  -0.25462158    2444.9333 
   20000   0.11801421   -3.0462201            0   -2.9975495  -0.23484136    2444.9333 
Loop time of 5.71207 on 1 procs for 20000 steps with 1724 atoms

Pair  time (%) = 4.62848 (81.0298)
Neigh time (%) = 0.305739 (5.35251)
Comm  time (%) = 0.0428324 (0.749857)
Outpt time (%) = 0.000311375 (0.00545117)
Other time (%) = 0.73471 (12.8624)

Nlocal:    1724 ave 1724 max 1724 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Nghost:    147 ave 147 max 147 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Neighs:    14384 ave 14384 max 14384 min
Histogram: 1 0 0 0 0 0 0 0 0 0

Total # of neighbors = 14384
Ave neighs/atom = 8.34339
Neighbor list builds = 723
Dangerous builds = 0
