Effect of the non-ideal axial ratio <i>c</i>/<i>a</i> on anharmonic EXAFS oscillation of h.c.p. crystals

The temperature and wavenumber dependence of the extended X-ray absorption fine-structure (EXAFS) oscillation hexagonal close-packed (h.c.p.) crystals have been calculated analyzed under effect non-ideal axial ratio c / a . anharmonic EXAFS is presented in terms Debye–Waller factor using cumulant expansion approach up to fourth order. An effective calculation model expanded developed from many-body perturbation correlated Debye potential. This potential, depending on , obtained first-shell near-neighbor contribution approach. A suitable analysis procedure performed by evaluating influence cumulants phase shift amplitude reduction oscillation. numerical results for crystalline zinc are found be good agreement with those experiments other theoretical methods at various temperatures. show that present essential improving accuracy analyzing experimental data signals h.c.p.