Soonsung So,
As I used HNEMD of 25nmx25nm graphene monolayers with compute commands, I
got the outputs containing heat currents by using 'jp' and 'jk' tags.
1. How can I change the unit of kinetic and potential parts of the heat
current vector to ones that contains joule(J) or Watts(W)?
From this manual page:
https://gpumd.zheyongfan.org/index.php/The_compute.out_output_file
you see that jp and jk are in units of eV^(3/2) amu^(-1/2). These
quantities have the dimension of [energy] x [velocity], and are called the
"heat currents" in my publications (and many other publications). If you
divide "heat currents" jp and jk by the corresponding volume V, you will
get the true "heat flux" which has the dimension of [energy power] /
[area], and then you can convert the units to W/m^2. I leave the details of
unit conversion as a high-school exercise for you :-)
2. How can I change those results to thermal conductivity?
After you get the "heat flux" (J/V) in units of W/m^2, you only need to use
equation (9) in my 2019-PRB (about HNEMD) to get the thermal conductivity:
kappa = (J/V) / (T*F_e).
Zheyong
