I am looking forward to simulate shock propagation using md simulation.
I am considering a diaphragm between high pressure and low pressure region. For equilibration NVT fix i used, at temperature 300 K. But while running the simulation, temperature attains 0 K. Could you please correct the error in my command.
I am attaching my code below.
LAMMPS input script for 2D shock propagation
Initialize simulation
units metal
dimension 2
boundary f p p
atom_style atomic
Create simulation box
region box block 0 10000 0 200 -0.5 0.5
create_box 1 box
mass 1 39.948
Define high and low pressure regions
region high_pressure block 0 10000 0 200 -0.5 0.5
region low_pressure block 1000 10000 0 200 -0.5 0.5
create_atoms 1 random 11941 12345 high_pressure
create_atoms 1 random 10852 54321 low_pressure
Define LJ potential
pair_style lj/cut 8.76
pair_coeff 1 1 0.01014 3.504
neighbor 0.3 bin
neigh_modify delay 0 every 100 check no
timestep 1
Set initial velocities
velocity all create 117 26563 mom yes rot yes
Set up the fixed wall
fix wall1 all wall/reflect xlo 1000 xhi 1000 units box
fix wall all wall/reflect xlo EDGE xhi EDGE
Thermostat for equilibration
fix equil all nvt temp 300 300 100
thermo 5000
thermo_style custom step temp press density
thermo_modify lost ignore
dump 1 all atom 100 shock_propagation.lammpstrj
Equilibrate the system
run 100000
Below, I am attaching my log file details.
LAMMPS (2 Aug 2023 - Update 3)
OMP_NUM_THREADS environment is not set. Defaulting to 1 thread. (src/comm.cpp:98)
using 1 OpenMP thread(s) per MPI task
Loaded 1 plugins from C:\Users\user\AppData\Local\LAMMPS 64-bit 2Aug2023\plugins
LAMMPS input script for 2D shock propagation in LJ units
Initialize simulation
units metal
dimension 2
boundary f p p
atom_style atomic
Create simulation box
region box block 0 10000 0 200 -0.5 0.5
create_box 1 box
Created orthogonal box = (0 0 -0.5) to (10000 200 0.5)
1 by 1 by 1 MPI processor grid
mass 1 39.948
Define high and low pressure regions
region high_pressure block 0 10000 0 200 -0.5 0.5
region low_pressure block 1000 10000 0 200 -0.5 0.5
create_atoms 1 random 11941 12345 high_pressure
Created 11941 atoms
using lattice units in orthogonal box = (0 0 -0.5) to (10000 200 0.5)
create_atoms CPU = 0.001 seconds
create_atoms 1 random 10852 54321 low_pressure
Created 10852 atoms
using lattice units in orthogonal box = (0 0 -0.5) to (10000 200 0.5)
create_atoms CPU = 0.001 seconds
Define LJ potential
pair_style lj/cut 8.76
pair_coeff 1 1 0.01014 3.504
neighbor 0.3 bin
neigh_modify delay 0 every 100 check no
timestep 1
Set initial velocities
velocity all create 117 26563 mom yes rot yes
Set up the fixed wall
fix wall1 all wall/reflect xlo 1000 xhi 1000 units box
fix wall all wall/reflect xlo EDGE xhi EDGE
Thermostat for equilibration
fix equil all nvt temp 300 300 100
thermo 5000
thermo_style custom step temp press density
thermo_modify lost ignore
dump 1 all atom 100 shock_propagation.lammpstrj
Equilibrate the system
run 1000000
Generated 0 of 0 mixed pair_coeff terms from geometric mixing rule
Neighbor list info …
update: every = 100 steps, delay = 0 steps, check = no
max neighbors/atom: 2000, page size: 100000
master list distance cutoff = 9.06
ghost atom cutoff = 9.06
binsize = 4.53, bins = 2208 45 1
1 neighbor lists, perpetual/occasional/extra = 1 0 0
(1) pair lj/cut, perpetual
attributes: half, newton on
pair build: half/bin/atomonly/newton
stencil: half/bin/2d
bin: standard
Per MPI rank memory allocation (min/avg/max) = 5.409 | 5.409 | 5.409 Mbytes
Step Temp Press Density
0 117 1.0931547e+28 0.75598921
5000 0 0 0.017811004
10000 0 0 0.017811004
15000 0 0 0.017811004
20000 0 0 0.017811004
25000 0 0 0.017811004
30000 0 0 0.017811004