Opticx

Official Resources

• Source Code: https://github.com/xatu-code/opticx
• Documentation: manual.pdf (in repo)
• License: See Repository

Overview

Opticx is a standalone Fortran code designed to evaluate n-order optical conductivities in periodic materials modeled with a Tight-Binding description. It serves as a companion tool to the Xatu code, enabling the calculation of non-linear optical properties and interfacing with Xatu to include excitonic effects in the optical response.

Theoretical Methods

• Optical Conductivity: Calculation of linear and non-linear (n-order) optical response.
• Tight-Binding: Operates on tight-binding Hamiltonian models.
• Wannier Interpolation: Uses wannierized band structures for high-resolution integration.
• Excitonic Effects: Interfaces with Xatu to include scaling/shifting based on BSE results.

Capabilities

• Band Structure Input: Reads wannierized Hamiltonians (e.g., from Wannier90).
• Non-Linear Optics: Calculation of high-order optical conductivities (SHG, THG, etc.).
• Exciton Integration: Can use output from Xatu to refine optical spectra with excitonic corrections.
• Periodic Systems: Optimized for crystals and 2D materials.

Implementation & Tech Stack

• Language: Fortran.
• Structure: Standalone binary with input/output file interfaces.
• Integration: Designed to work in a workflow with Xatu and Wannier90.

Citation

J.J. Esteve-Paredes, M. A. García-Blázquez, A. J. Uría-Álvarez, M. Camarasa-Gómez and J. J. Palacios, npj Computational Materials 11, 13 (2025).