AtC Example Files

I am interested in using AtC for some new research and am trying to run some examples. I am particularly interested in more complicated geometry than the simple thermal bar example which I have been able to run.

I am trying to run the semicircle example in the thermal directory. However it reads in a mesh file called “semicircle.mesh” which is not in any of the AtC example folders. I would like to understand the structure of the file starting with an example.

Can the mesh files be added to the AtC example folders?

Thanks,
William Evans Ph.D.
Research Associate
Focus Center
Rensselaer Polytechnic Institute
110 8th Street
Troy, NY 12180-3590
518-276-8826
evansw3@…707…

I am interested in using AtC for some new research and am trying to run some
examples. I am particularly interested in more complicated geometry than the
simple thermal bar example which I have been able to run.

I am trying to run the semicircle example in the thermal directory. However
it reads in a mesh file called “semicircle.mesh” which is not in any of the
AtC example folders. I would like to understand the structure of the file
starting with an example.

Can the mesh files be added to the AtC example folders?

please have a closer look at the example file, particularly the
comments. it contains apparently contains the input for *two* runs.
the (commented out) first part should generate this mesh file.

axel.

Hi William, we are looking into why the mesh files aren’t being transferred with the rest of files to the Lammps repo. In the meantime, I’ve attached the semicircle.mesh file to get you started.
Jeremy

semicircle.mesh (15.4 KB)

I have made some progress in understanding the AtC methods. I am ultimately interested in the two temperature method implemented with AtC because I can “control” what portion of the total simulation cell is applicable to TTM.

I am trying to understand the examples applicable to copper in the examples/user/atc//two_temperature folder and am having problems with the units in the Cu_ttm_mat file:

material Cu metal
heat_capacity constant
capacity 0.211977459280654
end
heat_flux linear
conductivity 67.4479848
end
electron_heat_flux linear
conductivity 441.362750535
end
electron_heat_capacity constant
capacity 0.005817388689
end
electron_phonon_exchange linear
coefficient 0.0156575679
end
end

The units should be in lammps metal units (e.g. ev, Ang, ps) but the values do not seem to be in these units? For example, total thermal conductivity should be on the order of .3 ev/Ang-K. Does the AtC implementation code perform some unit conversions? So far I have not found where that may be occurring?

Thanks for your help.

William Evans
Research Associate
Focus Center
Rensselaer Polytechnic Institute
110 8th Street
Troy, NY 12180-3590
518-276-8826
evansw3@…707…

Hi Bill, the AtC units system uses a consistent set of units based on Lammps’ length/mass/time/charge units. The only exception is the electric potential, which is consistent with Lammps’ electrical field units (usually volts). The “metal” keyword in the “material Cu metal” line denotes which set of units this is. The only units conversions under the hood are the ones transforming a quantity with an electric potential in it into something more useful, e.g. a force. I hope that helps. I will make sure this is added to the material file documentation I’m currently working on.
Jeremy