Square antiprisms can be capped on both square faces, giving bicapped square antiprismatic molecular geometry. The bicapped square antiprismatic atoms surrounding a central atom define the vertices of a gyroelongated square bipyramid. The symmetry group of this object is D.
Examples:
*BH, defined by the B framework
*[AsRh(CO)] and [SRh(CO)], defined by the Rh framework, which encapsulates the main group atoms As and S
*[TlSn], a zintl ion