[Wien] Rhombohedral to hexagonal problem

[Shu Miao]

Hello all,
My sample has rhombohedral structure (#166_R-3m). Using StructGen, I set
a=b=2.816A, c=14.049A, alpha=beta=90, and gamma=120. These are lattice
parameters in the hexagonal setting. However, after running x sgroup, the
parameters change to a=b=5.32147, c=26.54877, while the angles are same. I
cannon figure out how these numbers come out. Who can help? Thanks

Shu