Mass (The Ame2012 atomic mass evaluation (II) by M.Wang, G.Audi, A.H.Wapstra, F.G.Kondev, M.MacCormick, X.Xu, and B.Pfeiffer
Chinese Physics C36 p. 1603-2014, December 2012)
221.032040 ± 0.000210 (amu) [mass excess = 29845 ± 196 (keV) ]
[These values were derived from systematical trend]
Evaluated Data Libraries
Links to the libraries.
Parent Nuclides by Reactions in JENDL-4.0