Corundum
Tsirelson V, Antipin M, Gerr R, Ozerov R, Struchkov Y
Physica Status Solidi A87 (1985) 425-433
Ruby structure peculiarities derived from X-ray data. Localization of
chromium atoms and electron deformation density
_cod_database_code 1000017
_database_code_amcsd 0015110
4.7606 4.7606 12.994 90 90 120 R-3c
atom      x y      z
Al        0 0 .35217
O    .69365 0    .25