Looking for Structure of CrBi18O30

[Zhu Jianghai]

Hi, all,
        I am looking for the structure of CrBi18O30(tetragonal, a=7.748, c=5.728). If 
anybody know this structure, please inform me. Thanks in advance.

Zhu

===========================
Zhu Jianghai
Center for Analysis and Measurement
Fudan University
Shanghai 200437
P.R.China
===========================