Energy levels, radiative rates, and lifetimes for transitions in W XL

Abstract: Energy levels and radiative rates are reported for transitions in Br-like W XL, calculated with the general-purpose relativistic atomic structure package ({\sc grasp}). Configuration interaction (CI) has been included among 46 configurations (generating 4215 levels) over a wide energy range up to 213 Ryd. However, for conciseness results are only listed for the lowest 360 levels (with energies up to $\sim$ 43 Ryd), which mainly belong to the 4s$^2$4p$^5$, 4s$^2$4p$^4$4d, 4s$^2$4p$^4$4f, 4s4p$^6$, 4p$^6$4d, 4s4p$^5$4d, 4s$^2$4p$^3$4d$^2$, and 4s$^2$4p$^3$4d4f configurations, and provided for four types of transitions, i.e. E1, E2, M1, and M2. Comparisons are made with existing (but limited) results. However, to fully assess the accuracy of our data, analogous calculations have been performed with the flexible atomic code ({\sc fac}), including even a larger CI than in {\sc grasp}. Our energy levels are estimated to be accurate to better than 0.02 Ryd, whereas results for radiative rates (and lifetimes) should be accurate to better than $20\%$ for a majority of the strong transitions.