#123
P4/mmm
Example – Macedonite, PbTiO3 (@ T = 550 °C)
Named for the locality.
Powder profile refinement of lead zirconate titanate at several temperatures. II. Pure PbTiO3
Glazer A M, Mabud S A
Acta Cryst B34 (1978) 1065-1070
http://webmineral.com/data/Macedonite.shtml
CIF
http://rruff.geo.arizona.edu/AMS/download.php?id=10779.cif&down=cif
TiO6 octahedra (blue)
Pb (black)
The Fascination of Crystals and Symmetry 