Data and Code: Effective Residual Interaction Kernel Approach

Collective excitations such as excitons and plasmons critically shape optical spectra, yet remain computationally demanding to describe within the Bethe–Salpeter equation due to the complexity of the electron–hole interaction.In this work, the electron-hole interaction is exploited by decomposing the equation into two coupled Dyson equations: (i) a dominant, rapidly energy-dependent term capturing interactions between energetically close transitions, and (ii) a weaker, slowly varying term describing interactions between transitions distant in energy. While both contributions are required for accuracy, their distinct structure enables differentiated treatment. In particular, the second term is replaced by an effective scalar equation with a frequency-dependent interaction, based on a systematically improvable approximation.Applied to semiconductors and insulators, this approach reduces both construction and solution costs. The developed code implements this decomposition efficiently, while the datasets provide reference spectra and material benchmarks to quantitatively validate accuracy and scalability.