Multistep Approach for Simulating Raman Spectra of Amorphous Materials: The Case of Li3PS4 Glass Electrolyte.

Glasses are widely used for their various applications, which arise from their inherent lack of long-range ordering. This characteristic makes it challenging to describe their atomic properties. To facilitate and accelerate glass research, computational simulations, such as molecular dynamics or Monte Carlo simulations, are commonly employed to model the structure of these amorphous materials. However, verifying and later refining the models require comparing these simulations with spectroscopic data, which can be quite computationally challenging due to the number of atoms needed in the unit cell to account for the disorder. In this paper, we propose a multistep approach for simulating specifically Raman spectra that accounts for long-range interactions in amorphous materials. This approach, going from molecular dynamics to embedded cluster calculations, allows us to define the Raman signature of each structural unit and reconstruct the Raman spectrum of the glass electrolyte Li3PS4, achieving low computational cost and high agreement with existing spectroscopic experimental data.