Hi,
the errors you experienced are due to the fact that the tutorial was strongly outdated (it was done using ATK 2015.1), and did not reflect anymore the current implementation of the methods based on the Boltzmann Transport Equation to calculate the phonon-limited mobility. More specifically, the most important improvement is that ATK now makes full use of sparse matrices for the evaluation and storage of the electron-phonon coupling elements.
We have updated the tutorial, which now focuses specifically on the use of ATK for the efficient calculation of the phonon-limited mobility:
http://docs.quantumwise.com/tutorials/mobility/mobility.html
As you will see, the section on the use of the electron-phonon coupling analyzer for the analysis of the electron-phonon couplings is gone. The reason is that the workflow for this analysis has slightly changed with respect to ATK 2015.1, and will be part of a separate tutorial, which has already been planned. If you still want to perform this analysis before the tutorial is online, I suggest you to read carefully the chapter "Usage Examples" in the section about the ElectronPhononCoupling class in the ATK manual:
http://docs.quantumwise.com/manuals/Types/ElectronPhononCoupling/ElectronPhononCoupling.html
Citing literally:
"to visually ananlyze the coupling matrix elements with the ElectronPhononCoupling analyzer, it is advantagerous to calculate the matrix elements for all (k,q)-points. This is achieved by specifying a large energy tolerance, ‘energy_tolerance=100*eV’, like in the script below. In that case it will also be advantagerous to use a dense matrix representation. This can be specified by setting ‘store_dense_coupling_matrices=True’."Regards,
Daniele.