Lj reduced temperature problem

LAMMPS LAMMPS General Discussion
1

Hello,

I am facing a problem with the temperature calculation for LJ fluids. For T* = kT/ε, which ε should I use if I have different interaction strength between different groups?

For example, one of my coarse-grained systems have εAA=3 and εBB=1. The Lorenz-Berthelot mixing rule εAB = sqrt(εAA * εBB) is the only mathematical formula I have found, but using εAB as the overall ε for the temperature calculation does not seem very accurate.

Any insight is highly appreciated. Thank you!

2

It must be \varepsilon \mathrm{BB} since technically it is value is not plain 1.0, but 1.0 \varepsilon^*

3

Thank you. Is it a matter of using the baseline value as reference? I guess the more simplified question would be, if we had εAA=1 and εBB=0.33 (which is basically the same relative strength as my original question), should we still use εBB?

4

No. Please see my explanation in the previous response.