Usage

EDI requires the wavefunction and perturbation potential obtained from first principle code as input data for calculations. Currently, QE is the supported DFT engine. Here are some details on using EDI.

Running

To run edi, use the following command:

$ mpirun -np $N edi.x -ni $N  >output

The input file is predefined text file calcmdefect.dat. The output file contains calculation procedure information. By default, a moderate level of debug information is output. For more information, current code needs uncommenting. In the future, a flag controled debug verbosity level would be supported.

Parallelization level

EDI is parallelized over k point pairs. EDI uses optimized algorithm to calculate different part of scattering matrix element, acheiving the optimal performance of accuracy and effeciency. The k point pair parallelization is acheived by assigning different k point pairs to different process images. Each image generates an output file, with file name out.i_0, where i is the image index. The needed matrix element could be found from the out put file, if the run is interrupted.

Optimization and scaling

The scalability of EDI is linear with system size. Namelhy the calcualtion cost scales linearly with the volum of super cell, making it capable of calculating large systems easily. Calculation of matrix element is parallelizede over k point pairs. EDI could easily run on large HPCs and utilize the full capacity. Here the number of core is $N, it could be any value divisible by the total number of kpoint pairs for optimal performance.

Postprocessing

After a successful run, the output files will be generated. The default file name is pp.dat. It could be used to calculate the carrier mobility.

Calculating mobility

To calcualted the transport mobility, the postprocessing script mu.py could be used.

$ python mu.py

Out put data containing the transport properties, including scattering rate and mobility, will be written automatically.

Note

Currently, the hexangonal lattice 2D materials are tested, support for other types of lattice or 3D structures are unstable.