Dear All,
I would like to calculate the thermal conductivity of a simple one component LJ system using LAMMPS. The Green-Kubo relation to calculate thermal conductivity (lambda) is:
lambda = ( 1/(3VkB*T^2) ) * Integral( 0 to infinity){ <j(0)j(t)>} dt
where
j(t) = sum (over i) {v ei} + 0.5* Sum (over i,j; i not eq j) { (Fij dot vi) rij }
However, I have not been able to locate the variable, (if it exists) that gives the force between a given pair of particles. This would be required to perform the above calculation.
Please can you point me as to whether such a variable exists / any other way I can get a handle to this quantity.
If not, could you please provide access to this variable in the next release of LAMMPS? Similarly, a variable that gives the potential between two specified particles would also be helpful.
Any suggestions in performing the above calculations are welcome.
Cheers!
Mario Pinto
PS: I have looked at the thermal/conductivity fix, but that works only for particles of the same mass; However in the near future I would like to carry out computations for systems consisting of a mixture of particles.