Codes

GNNOpt

QERaman

An ensemble-embedding graph neural network for direct prediction of optical spectra from crystal structures.

Input: Crystal structure data (e.g. cif file)

Output: Complex dielectric function, absorption coefficient, complex refractive index, and reflectance.

Machine learning: Equivariant graph neural networks.

Applications: Screening photovoltaic and quantum materials.

Published paper: N. T. Hung*, R. Okabe, A. Chotrattanapituk and M. Li*, Universal ensemble-embedding graph neural network for direct prediction of optical spectra from crystal structure, Adv. Mat. 36, 2409175-1-11 (2024).

Source files of the GNNOpt at

QERaman

QERaman

An open-source program for computing the first-order resonance Raman spectroscopy based on Quantum ESPRESSO.

Compatible: Quantum ESPRESSO

Command: bands_mat.x, ph_mat.x, raman.x

Output: Electron-photon and electron-phonon matrix elements, first-order resonance Raman tensor and spectra as a function of incident laser energy for linearly- or circularly-polarized light.

Published paper: N. T. Hung*, J. Huang, Y. Tatsumi, T. Yang, and R. Saito*, QERaman: An open-source program for calculating resonance Raman spectra based on Quantum ESPRESSO, Comput. Phys. Commun. 295, 108967 (2024).

Source files of the QERaman at

QR2-code

QR2-code

A DFT-based program for computation and analysis of the resonant Raman spectra.

Compatible: Quantum ESPRESSO, EPW

Command: epw.x (modified), matdyn.x (modified), phonon sort.x, raman pp.x

Output: Single, double and defect-induced double resonant Raman.

Website: http://qr2-code.com

Note: QERaman is based on only Quantum ESPRESSO, while QR2-code is based on both Quantum ESPRESSO and EPW. QERaman has fewer parameters and is simpler than QR2-code. Thus, we recommend QERaman for people who focus only on first-order Raman calculation. If you want to calculate the high-order Raman spectra, the QR2-code is recommended.

Published paper: J. Huang*, R. Liu, Y. Zhang, N. T. Hung*, H. Guo, R. Saito and Teng Yang*, QR2-code: An open-source program for double resonant Raman spectra, arXiv.2505.10041 submitted.

Source files of the QR2-code at