| 
| 166Er | Half-life | Boson, 68p 98n |  |  | Stable | Spin 0 Parity 1 | 
 This isotope is stable and thus has no decay products, so instead we show decay chains that lead down to it.
 | | Atomic Weight | 165.930293061 |  | Abundance | 33.503% |  | Mass Excess | -64.931595MeV |  | Binding Energy | 8.141992MeV |  | Magnetic Moment | 0 μ |  | Quadrupole Moment | N/A | 
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