Anharmonic Debye-Waller Factor for the Atom of 4/mmmSite Symmetry

Abstract
Generalized Debye-Waller factor for the atom of 4/ m m m site symmetry were formulated on the basis of classical Einstein oscillator model. In this formulation the effect of the fourth order anharmonic terms of one particle potential was taken into account. It is found that four anharmonic parameters are necessary in addition to two harmonic temperature parameters to describe the generalized Debye-Waller factor for this atom.