Pedio, M.Wu, Z. Y.Benfatto, M.Mascaraque Susunaga, ArantzazuMichel, E.Ottaviani, C.Crotti, C.Peloi, M.Zacchigna, M.Comicioli, C.2023-06-202023-06-202002-10-010163-182910.1103/PhysRevB.66.144109https://hdl.handle.net/20.500.14352/59404© 2002 The American Physical Society. One of the authors (Z.Y.W.) acknowledges the financial support of the 100-Talent Research Program of the Chinese Academy of Sciences and of the Outstanding Youth Fund (No. 10125523) of the National Natural Science Foundation of China.The high-energy resolution O K-edge absorption near-edge x-ray absorption fine structure spectrum has been measured for in situ prepared potassium superoxide. The experimental data have been analyzed in detail by multiple scattering calculations using self-consistent field potentials. In particular, the so-called π resonance at the rising edge, which presents a double-peak structure, has been totally resolved and reproduced by the calculations. This analysis indicates that the grown material is arranged in a KO_2 structure with an O-O distance between 1.31 and 1.34 Angstrom. Moreover, the calculation demonstrates both a complete ionic character of the bound between the Oˆ(2-) anion and K atoms and a strong interaction between the anion and solid-state matrices.engjournal articlehttp://dx.doi.org/10.1103/PhysRevB.66.144109http://journals.aps.orgopen access538.9AbsorptionSpectraSchemeEdgeFísica de materiales