Hello,
I am following the langevin example to calculate the thermal conductivity of a material.
https://github.com/lammps/lammps/tree/master/examples/KAPPA
In the method you thermostat a hot and cold region:
region hot block INF INF INF INF 0 1
region cold block INF INF INF INF 10 11
compute Thot all temp/region hot
compute Tcold all temp/region cold
And then following this part in the README:
dQ = 8000 * 0.5*(0.905+0.947) / 100 / 18.82^2 / 2
8000 atoms
0.5*(0.905+0.947) = from log file =
ave of total in/out energy for 2 regions normalized by # of atoms
100 = 20,000 steps at 0.005 tau timestep = run time in tau
xy box area = 18.82^2
divide by 2 since energy flux goes in 2 directions due to periodic z
dTemp = 0.578 from log file for average Temp difference between 2 regions
dZ = 18.82
Here’s my question: If you change the region sizes, the cumulative in/out energy will change…bigger regions will have more energy, smaller regions have smaller energies…so what number of atoms do you normalize by?
Thanks,
Stacey