SQUARE PYRAMID COORDINATION

There is a tetragonal cell (P4/mmm) of all square pyramid coordination that I thought of and showed to Professor O'Keeffe in an email exchange and he showed me that it was already proposed by his people...it was comprised of 2 opposing square pyramid coordination sites linked to other such opposed dimeric square pyramid coordination units...I do not know the stoichiometry from memory but the Schlaefli symbol was (5 1/5, 5) I believe. It was almost the continuation of the sequence (3, 3), the tetrahedron to (4, 4) the square net...on to (5, 5) as a novel 3D network...almost but not quite.