Atomic thermal vibrations in semiconductors: Ab initio calculations and EXAFS measurements

The non-standard cumulant analysis has been used to disentangle the various phonon displacement cumulants up to 4th order and 3rd neighbors. Ab initio phonon dynamics has been employed to compute the correlation functions lip to 8th neighbors and Debye-Waller factors in the harmonic approximation. Excellent agreement between experimental and theoretical data is obtained.