XAS involves the interaction of X-rays with matter, where the absorption of X-rays by a sample results in the excitation of core electrons to unoccupied states. The X-ray Absorption Near Edge Structure (XANES) region provides information about the oxidation state and local geometry of the absorbing atom, while the Extended X-ray Absorption Fine Structure (EXAFS) region gives details about the distances, coordination numbers, and types of neighboring atoms.
