EXAFS curved-wave theory

Gurman SJ, Binsted N, Ross I (1984) A rapid, exact curved-wave theory for EXAFS calculations. J de Physique C 17 143-151... 

Figure 10 (a) EXAFS spectrum and (b) Fourier transforms for FeCl2 isolated in solid CO (—) experiment ( ) curved wave multiple scattering theory for tra r-Cl2Fe(CO)4. (Reprinted with permission from Ref 14. 1992 American Chemical Society)... 

Belli M, Scafati A, Bianconi A, Mobilio S, Palladino L, Reale A, Burattini E (1980) X-ray absorption nearedge stractures (XANES) in simple and complex Mn compounds. Solid State Commun 35 355-361 Benfatto M, Congiu Castellano A, Daniele A, Della Longa S (2001) MXAN A new software procedure to perform geometrical fitting of experimental XANES spectra. J Synchrotron Rad 8 267-269 Benfatto M, Natoli CR, Brouder C, Pettifer RF, Ruiz Lopez MF (1989) Polarized curved wave EXAFS Theory and apphcation. Phys Rev B39 1936-1939... 

Fig. 13. Pictorial view of the final-state radial wave functions relevant for core transitions in a molecule. The core transitions take place in an effective molecular potential seen by the excited photoelectron. The final states in the continuum XANES region are quasi-bound multiplescattering resonances (MSR), also called shape resonances. Below the continuum threshold E0 transitions to unoccupied valence states appear. 0 is the energy of the core ionization potential (from ESCA). Ec is the energy where the wavelength of initially excited photoelectrons conforms to the interatomic distance. For E < E0, discrete transitions to unoccupied valence states. E0 < E < Ec, continuum XANES. For < Ec, the EXAFS theory breaks down. The dotted curves show the wave functions of the initially excited photoelectron. From Bianconi (30).

---