LayerOptics: Microscopic modeling of optical coefficients in layered materials

TL;DR

LayerOptics is a computational tool that accurately models optical coefficients in layered anisotropic materials by solving Maxwell's equations, bridging the gap between first-principles calculations and experimental measurements.

Contribution

We introduce LayerOptics, a new implementation that computes optical coefficients from dielectric tensors considering anisotropy, enhancing the microscopic understanding of spectroscopic properties.

Findings

Good agreement with experimental data across frequency ranges

Highlights the importance of combining ab initio methods with Maxwell's equations

Demonstrates applicability to complex layered materials

Abstract

Theoretical spectroscopy is a powerful tool to describe and predict optical properties of materials. While nowadays routinely performed, first-principles calculations only provide bulk dielectric tensors in Cartesian coordinates. These outputs are hardly comparable with experimental data, which are typically given by macroscopic quantities, crucially depending on the laboratory setup. Even more serious discrepancies can arise for anisotropic materials, e.g., organic crystals, where off-diagonal elements of the dielectric tensor can significantly contribute to the spectral features. Here, we present LayerOptics, a versatile and user-friendly implementation, based on the solution of the Maxwell's equations for anisotropic materials, to compute optical coefficients in anisotropic layered materials. We apply this tool for post-processing full dielectric tensors of molecular materials, including excitonic effects, as computed from many-body perturbation theory using the exciting code. For prototypical examples, ranging from optical to X-ray frequencies, we show the importance of combining accurate ab initio methods to obtain dielectric tensors, with the solution of the Maxwell's equations to compute optical coefficients accounting for optical anisotropy of layered systems. Good agreement with experimental data supports the potential of our approach, in view of achieving microscopic understanding of spectroscopic properties in complex materials.