[lammps-users] KAPPA in.langevin NEMD Direct Method

Dear All,

I’m trying to calculate thermal conductivity of a nanofluid using the direct method. I emulated what’s been done in the in.langevin KAPPA example. However, I get values of zero for Thot and Tcold.

Please find my Input script and logfile attached.

What am I doing wrong? Why am I getting zero values?

Best regards,
Yunes Salman

in.cu (4.54 KB)

log.lammps (15 KB)

that would happen, for example, if there are no atoms in your hot/cold region.

please also note that the example input uses reduced units while you are using real units so some adjustments need to be made to factor in constants that would be 1.0 in lj units, and also that the thermostat regions have been placed correctly.

debugging regions can be easily done by using the “set” command to change some atom property (e.g. type or molecule id or velocity) first for all atoms to one value and then for the atoms in the region to a different value. after dumping the geometry with that property changed you can easily check whether the region is properly located.

also, you should confirm that you get the desired linear change of temperature between the hot and cold area as required by the method.

please read up on the method to make certain