Anharmonic Effective Pair Potentials of KBr and CsBr Determined by EXAFS
نویسندگان
چکیده
The anhamtonic effective pair potentials ~(u)=au~~+~u~/3!+yu~/4! in K& and CsBr have been investigated at room temperature by the EXAFS technique. In the parameter fitting, we have directly carried out the numerical integration of EXAFS function and evaluated the anharmonic effective pair potential. The Griineisen parameters y, were calculated from the obtained values of a and 6 as 1.65 for KBr and 1.37 for CsBr, respectively. Contribution of the van der Wads term to the total energy has been detennhed by comparing with the calculated curve obtained by the empirical estimation, and rises from 1.8 % for KBr to 3.0 % for CsBr.
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