Neptunium-alpha
Wyckoff R W G
Crystal Structures 1 (1963) 7-83
Second edition. Interscience Publishers, New York, New York
Sample is stable at room conditions
_database_code_amcsd 0011263
4.723 4.887 6.663 90 90 90 Pmcn
atom   x    y    z
Np1  .25 .208 .036
Np2  .25 .842 .319