An implementation of the methodology pioneered by Alkauskas et al. for computing nonradiative recombination rates from first principles. The code includes various utilities for processing first principles calculations and preparing the input for computing capture coefficients. More details on the implementation of the code can be found in [our recent paper](). Documentation for the code is hosted on Read the Docs.
NONRAD is implemented in python and can be installed through pip
.
Dependencies are kept to a minimum and include standard packages such as numpy
, scipy
, and pymatgen
.
As always with python, it is highly recommended to use a virtual environment. To install NONRAD, issue the following command,
$ pip install nonrad
or to install directly from github,
$ pip install git+https://github.com/mturiansky/nonrad
NONRAD can use numba
to accelerate certain calculations.
If numba
is already installed, it will be used;
otherwise, it can be installed by specifying [fast]
during installation with pip, e.g.
$ pip install nonrad[fast]
To install NONRAD for development purposes, clone the repository
$ git clone https://github.com/mturiansky/nonrad && cd nonrad
then install the package in editable mode with development dependencies
$ pip install -e .[dev]
pytest
is used for unittesting.
To run the unittests, issue the command pytest nonrad
from the base directory.
Unittests should run correctly with and without numba
installed.
A tutorial notebook that describes the various steps is available here. The basic steps are summarized below:
get_cc_structures
function. Extract the relevant parameters from the configuration coordinate diagram, aided by get_dQ
, get_PES_from_vaspruns
, and get_omega_from_PES
.VASP
). Extraction of the matrix elements are facilitated by the get_Wif_from_wavecars
or the get_Wif_from_WSWQ
function.sommerfeld_parameter
and/or charged_supercell_scaling
.get_C
.To contribute, see the above section on installing for development. Contributions are welcome and any potential change or improvement should be submitted as a pull request on Github. Potential contribution areas are:
If you use our code to calculate nonradiative capture rates, please consider citing
@article{alkauskas_first-principles_2014,
title = {First-principles theory of nonradiative carrier capture via multiphonon emission},
volume = {90},
doi = {10.1103/PhysRevB.90.075202},
number = {7},
journal = {Phys. Rev. B},
author = {Alkauskas, Audrius and Yan, Qimin and Van de Walle, Chris G.},
month = aug,
year = {2014},
pages = {075202},
}
and
@article{turiansky_nonrad_2021,
title = {Nonrad: {Computing} nonradiative capture coefficients from first principles},
volume = {267},
doi = {10.1016/j.cpc.2021.108056},
journal = {Comput. Phys. Commun.},
author = {Turiansky, Mark E. and Alkauskas, Audrius and Engel, Manuel and Kresse, Georg and Wickramaratne, Darshana and Shen, Jimmy-Xuan and Dreyer, Cyrus E. and Van de Walle, Chris G.},
month = oct,
year = {2021},
pages = {108056},
}
If you use the functionality for the Sommerfeld parameter in 2 and 1 dimensions, then please cite
@article{turiansky_dimensionality_2024,
title = {Dimensionality Effects on Trap-Assisted Recombination: The {{Sommerfeld}} Parameter},
shorttitle = {Dimensionality Effects on Trap-Assisted Recombination},
author = {Turiansky, Mark E and Alkauskas, Audrius and Van De Walle, Chris G},
year = {2024},
month = may,
journal = {J. Phys.: Condens. Matter},
volume = {36},
number = {19},
pages = {195902},
doi = {10.1088/1361-648X/ad2588},
}