Dear lammps users,
I have three questions to ask you.
a) Do you know which command can perform a 1D simulation in lammps, such as the command fix enforce2d does?
b) In the low dimensional systems(1D and 2D), the thermal conductivity diverges inherently with the increasing system size. Due to this reason, the flux autocorrelation function will have long tail which results in the divergence of the thermal conductivity kappa when we use the Green-Kubo method to integrate the flux autocorrelation function. Does the command “calculate heat/flux” consider this singularity of low dimensional systems?
c) In the low dimensional systems(1D and 2D), the temperature gradient is inherently not linear, such as the 1D FPU-beta model. So why do we adjust it to the original nonexistent linearity when we use the fix thermal/conductivity?