MgSe
Wyckoff R W G
Crystal Structures 1 (1963) 85-237
Second edition. Interscience Publishers, New York, New York
rocksalt structure
_database_code_amcsd 0011351
5.451 5.451 5.451 90 90 90 Fm3m
atom  x  y  z
Mg    0  0  0
Se   .5 .5 .5