Temperature-dependent High-order XAFS Cumulants of Gaseous Bromine Calculated Based on the Classical Statistical Theory

The anharmonic X-ray absorption fine structure (XAFS) cumulants of gaseous bromine (Br2) in an expansion to the 4th order have been calculated under the influence of thermal disorder. The thermodynamic parameters of Br2 have considered the influence of nearest neighbors on the backscattering and absorbing atoms. The temperature-dependent XAFS cumulants were calculated explicitly and simply from the calculation model developed based on the classical statistical theory within the correlated Einstein model. The obtained numerical results of Br2 at temperatures from 0 to 600 K fit with those obtained from the experimental XAFS data and other theoretical approaches at various temperatures. These results indicate that the present theoretical model helps analyze experimental XAFS signals of gaseous bromine and other gases.