[lammps-users] hugoniostat simulation

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1

Hii all,

I am carrying out a hugoniostat simulation on Al. The script I have used
is the one available on LAMMPS website for a LJ fcc solid. I have
converted this script into metal units and want to perform a hugoniostat
simulation for Pzz=20 GPa for ALuminium FCC crystal. I have first
minimized the system using ‘box/relax’ and ‘miminize’ commands. Further,

compressed the system using ‘hugoniostat’ as given in the script.

When the run corresponding to the compression starts, all the

parameters (temp, kinetic energy , pressure etc) starts diverging with time as can
be seen in the output file attached. I could observe that the potential
Energy (4th column, E_pot in the output file) being calculated by LAMMPS
is 0 which may be a source of this divergence during the evolution in
the system. Can anyone tell why this script is giving zero potential
energy throughout the evolution. Input file is also attached.

Regards,
Nidhi

in.txt (5.01 KB)

Al.eam.alloy (576 KB)

out.out (115 KB)

2

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the system. Can anyone tell why this script is giving zero potential
energy throughout the evolution. Input file is also attached.

simple. Unlike the lj/cubic pair style in the example input, the eam/alloy pair style and its parameters are not stored in restart files and thus when you are using “clear” and then “read_restart” after the minimization you are switching to a model where atoms have no interactions; hence the 0 for potential energy.

I also note that you are using a very old version of LAMMPS (almost 5 years old) which has known bugs, is missing features and specifically does not print a warning when restarting with a pair style that doesn’t support restarting. Thus strongly recommend to use a newer version.

Axel.