W L₃-edge x-ray study of 5d orbital excitations in WSe₂ and WTe₂

Two tungsten-based transition metal dichalcogenides (TMDs), tungsten diselenide (WSe₂) and ditelluride (WTe₂), offer suitable model systems for investigating the interplay between crystal structures and 5d-orbital hybridization in layered transition-metal systems. Using W L₃-edge x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS), we directly investigate the W 5d electronic states in polycrystalline TMDs samples. Combined with structural analyses, the white-line peaks in the XAS spectra, examined by their first-derivative peak positions, indicate symmetry-driven orbital states of WSe₂ and WTe₂. The corresponding RIXS spectra exhibit clearly distinct dd-excitations, indicating differences in W 5d orbital occupancy and ligand hybridization between the two compounds. This study provides a spectroscopic framework for understanding electronic structures of tungsten dichalcogenides in relation to chalcogen coordination changes and their topological and catalytic properties.