Gm. Bendele et al., OCTAHEDRAL CATIONS IN RB3C60 - RECONCILIATION OF CONFLICTING EVIDENCEFROM DIFFERENT PROBES, Europhysics letters, 41(5), 1998, pp. 553-558
There is an apparent contradiction between X-ray diffraction, NMR and
extended X-ray-absorption fine-structure (EXAFS) measurements on the s
tructure of Rb3C60. Specifically, a possible displacement of the octah
edral alkali cations away from their site center and the origin of a t
hird observed Rb NMR line have been widely discussed. We address this
question with X-ray powder diffraction as a function of temperature an
d find that the octahedral cation does have its equilibrium position a
t the site center with a large Debye-Waller factor. We show how this r
esult can be reconciled with results of NMR and EXAFS.