Dear Lammps users,

I am trying to calculate viscosity of an amorphous system at 300 K (after quenching) using the equilibrium method with the Green-Kubo formula but I get I completly wrong result about 1 (Pa*sec) while a value higher than 10^12 (Pa*sec) is expected.

I used the script that from the viscosity examples and I converted the units from metal to SI. I also read previous messages with similar problems but I didn’t figure out how to solve my problem. Do you have any suggestion or idea of what maybe the problem?

Thanks a lot in advance ,

Alex

Here is the input that i used

# Sample LAMMPS input script for viscosity AAAAAAAAA

variable T equal 300

variable V equal vol

variable dt equal 0.001

variable p equal 200 # correlation length

variable s equal 1 # sample interval

variable d equal $p*$s # dump interval

# convert from LAMMPS real units to SI

variable kB equal 1.3806504e-23 # [J/K/** Boltzmann

variable bar2Pa equal 100000.0

variable A2m equal 1.0e-10

variable ps2s equal 1.0e-12

variable convert equal {bar2Pa}*{bar2Pa}*{ps2s}*{A2m}*{A2m}*{A2m}

units metal # Angstrom, eV, ps, bar

boundary p p p # Periodic boundaries in all dimensions.

atom_style atomic # Pair potentials.

atom_modify map array