Levels inOs186as Populated from Decay of 15.8-hIr186

The level scheme of ${}_{}{}^{186}{}_{}{}^{}\mathrm{Os}$ as populated by the decay of 15.8-h ${}_{}{}^{186}{}_{}{}^{}\mathrm{Ir}$ has been studied using Ge(Li) detectors in singles and coincidence spectrometers. The coincidence data confirm essentially all of the previously known intraband and interband transitions assigned to the ground-state band (to the $6^{+}$ level), the $\gamma$ band (to the $7^{+}$ level), and to the $I=4,5,\mathrm{and} 6$ members of a two-phonon $K=4\mathrm{}$ band. Coincidence data also establish levels in keV at 1194.45, ($4^{+}$); 1461.09, $4^{+}$; 1480.3, $4^{+}$; 1628.3, $5^{-}$; 1775.8, $6^{+}$; 1812.5, $5^{+}$; 1875.40, $4^{+}$; 2056.38, ($5^{+}$, $6^{+}$); 2081.21, $4^{+}$; 2377.3, ($5^{+}$, $6^{+}$); and 2771.7, $4^{+}$. The $I^{\pi }$ assignments are based on multipolarities determined from internal-conversion coefficients. Additional levels based on energy sums are tentatively proposed at 1582.3, 2661.2, 3041.3, 3151.7, 3268.8, and 3413.6 keV. The 15.8-h $1^{186}$Ir state is believed to have $I^{\pi }=5^{+}$ and an argument is presented based on the $\beta$-decay pattern that $K=1\mathrm{}$.