AB-INITIO CALCULATIONS OF EXAFS DEBYE-WALLER FACTORS FOR 2-DIMENSIONAL AND 3-DIMENSIONAL CRYSTALS

We study the temperature dependences of EXAFS Debye-Waller factors for two-and three-dimensional high symmetric crystals based on the previo usly developed first principle quantum statistical theory. The nearest neighbor interatomic potential is taken into account by use of the an harmonic Morse potential. Availability of Debya and Einstein approxima tion is investigated for a two-and three-dimensional diatomic model. T he harmonic Debye-Waller factors for first and second-shell atoms are calculated and we find quite similar behaviors to those for one-dimens inal crystals.