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First-principles photoluminescence lineshapes, electron–phonon coupling, and
electronic-state localization for point defects in semiconductors and insulators.

PyPI Conda Downloads MIT Python 3.10+

Capabilities

🌈 PL Lineshapes

Multi-phonon photoluminescence spectra via the generating-function approach (Alkauskas et al. 2014).

📊 Huang–Rhys Factors

Mode-resolved partial HR factors Sk and the continuous spectral density S(ω) from displacement or vertical-force data.

🔬 Electronic Localization

P-ratio and IPR from VASP PROCAR — identify defect-character Kohn–Sham states without pydefect.

⚛️ Phonon Analysis

Phonon IPR, localization ratio, and phonopy integration for force-constant extraction and Γ-point band structures.

📐 Configuration Coordinate

ΔQ, ΔR, parabolic PES fitting, Stokes shift, and vertical transition energies from interpolated supercell calculations.

🖼️ Publication Plots

Ten standard diagnostic plots — intensity, S(ω), IPR, HR scatter — plus KS level diagrams coloured by P-ratio.

Quick install

pip install "defectpl[all]"

pip install defectpl

conda install -c conda-forge defectpl

Five-minute example

from pymatgen.core import Structure
from defectpl.phonon import read_band_yaml
from defectpl.vasp_wrapper import calc_dR
from defectpl.defectpl import Photoluminescence

gs = Structure.from_file("CONTCAR_gs")
es = Structure.from_file("CONTCAR_es")
frequencies, eigenvectors, masses = read_band_yaml("band.yaml")

pl = Photoluminescence(
    frequencies=frequencies,
    eigenvectors=eigenvectors,
    masses=masses,
    EZPL=1.945,        # Zero-phonon line energy in eV
    dR=calc_dR(gs, es),
    gamma=2.0,         # ZPL broadening in meV
)

print(f"Huang–Rhys factor  S = {pl.HR_factor:.3f}")
print(f"Debye–Waller factor  = {pl.DW_factor:.4f}")

pl.generate_plots(out_dir="./plots/", fig_format="png")

Cite

If you use DefectPL in published work, please cite:

Shibu Meher et al., Carbon with Stone-Wales Defect as Quantum Emitter in h-BN, Phys. Rev. B 111, 104109 (2025). doi:10.1103/PhysRevB.111.104109

Shibu Meher et al., High-throughput Computational Search for Group-IV-related Quantum Defects as Spin-photon Interfaces in 4H-SiC, Phys. Rev. B 112, 184112 (2025). doi:10.1103/PhysRevB.112.184112

Acknowledgements

DefectPL implements the generating-function formalism of Alkauskas, Buckley, Awschalom & Van de Walle (New J. Phys. 16, 073026, 2014) and the Franck–Condon overlap approach of Alkauskas, Yan & Van de Walle (Phys. Rev. B 90, 075202, 2014). Electronic P-ratio follows Kumagai et al. (Phys. Rev. B 103, 104102, 2021).