[lammps-users] flow of liquid argon


I have been doing the simulation of a flow of liquid argon in real units, but argon is still solid in the simulation, even the temperature is about 85 K.
Pressure of a system is about 3500 atm, it's looks unreal.
Could you suggest me anything?

Thanks, Sergey R.

You might double check to make sure the code is using the thermo_modify temp to adjust the kinetic contribution to the pressure tensor. I seem to remember some discussion of this in the past, but I don't know where it went. Anyway,if it's not, your pressure might not be as large as it appears.

Quoting "Romashevsky S." <[email protected]>:

Thanks for your response,

Of course, I have checked that the thermo_modify temp is used to adjust the kinetic contribution to the pressure tensor, but result is unbelievable.

05.06.2010 23:49, Matt K. Petersen пишет:

The state of a LJ system is not only given by temperature, but also
depends on density/pressure (search for Lennard-Jones phase diagram on
google or google scholar).

In your input script the lattice parameter (5.25 Angstrom) is
significantly smaller than the equilibrium one of a fcc solid of LJ
atoms with sigma = 3.405 Angstrom. So you cannot expect to get a
liquid since your density is much too high for that. You will rather
get a strongly compressed solid, hence the large pressure in your
system. You can try to reduce the density, or equivalently to increase
the lattice parameter in the lattice command to obtain a liquid.

Best regards,