### DEFINE SIMULATION BOX GEOMETRY ###
variable d equal 0.8
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 2.8
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 ###
unfix nvt
fix nvt all nvt temp ${T} ${T} ${tdamp}
thermo_style custom step etotal temp press density
variable etot equal etotal
variable etot2 equal etotal*etotal
variable temp equal temp
fix aves all ave/time 100 1000 100000 v_etot v_temp v_etot2
run 100000

variable aveetot equal f_aves[1]
variable avetemp equal f_aves[2]
variable aveetot2 equal f_aves[3]
variable varetot equal f_aves[3]-f_aves[1]*f_aves[1]


print "Averages"
print "--------"
print "Energy: ${aveetot}"
print "Temperature: ${avetemp}"
print "Energy Variance: ${varetot}"