Generalized energy-based fragmentation TDDFT-ris method and its application to electronic spectra and asymmetry factors of large systems

Accurately and efficiently calculating electronic excited states remains a major challenge in quantum chemistry, especially for complex photo-physical and photochemical systems. Conventional approaches such as time-dependent density functional theory (TDDFT) are limited by unfavorable computational scaling, limiting their applicability to large systems. To address this, we present a computational framework combining the generalized energy-based fragmentation (GEBF) approach with TDDFT-ris, which requires only one s-type auxiliary basis function per atom via the resolution-of-the-identity technique. This approach enables efficient and reliable excited-state computations for macromolecules, including fluorescent materials and proteins with thousands of atoms, and provides accurate predictions of asymmetry factors (g-factors) in chiral optoelectronic materials and fluorescent protein.