Greetings,

I have a system of methane/water mixture, and I have a lammps scripts that calculate the single-phase viscosity using the Green-Kubo relation. Can I use this GK relation to determine the viscosity of this new multi-component system? I mean, technically, the formula will give me a value, but is this reliable? Can I somehow revise the script such that it calculates the viscosities of water and methane separately?

Here is the lammps script to calculate viscosity:

variable pxy equal pxy

variable pxz equal pxz

variable pyz equal pyz

fix SS all ave/correlate $s $p $d v_pxy v_pxz v_pyz type auto file S0St.dat ave running#fix SS all ave/correlate/long $s $d v_pxy v_pxz v_pyz

variable scale equal {convert}/({kB}

$T)$V*s*{dt}

variable v11 equal trap(f_SS[3]){scale} variable v22 equal trap(f_SS[4])*{scale}${scale}

variable v33 equal trap(f_SS[5])

variable vis equal (v_v11+v_v22+v_v33)/3.0