Dear All,
thank you very much for your comments.
In fact my material is hexagonal. A study on the systematic absences did not
allow a unique assignment of the space group and six possible solutions were
determined: P63mc (No. 186), P-62c (No. 190), P63/mmc (No. 194), P3c1 (No. 158)
and P-31c (No. 163). I tried to solve the structure in all these space groups
but the only successful solution appeared in P63mc (No. 186). The structure can
be drawn and all atomic distances and angles look ok.
Stanislav
