  We have developed a broadly-applicable approach that drastically increases
the ability to accurately predict properties of complex atoms. We applied it to
the case of Ir$^{17+}$, which is of particular interest for the development of
novel atomic clocks with high sensitivity to the variation of the
fine-structure constant and dark matter searches.
  The clock transitions are weak and very difficult to identity without
accurate theoretical predictions. In the case of Ir$^{17+}$, even stronger
electric-dipole (E1) transitions eluded observation despite years of effort
raising the possibility that theory predictions are grossly wrong. In this
work, we provide accurate predictions of transition wavelengths and E1
transition rates in Ir$^{17+}$. Our results explain the lack of observation of
the E1 transitions and provide a pathway towards detection of clock
transitions. Computational advances demonstrated in this work are widely
applicable to most elements in the periodic table and will allow to solve
numerous problems in atomic physics, astrophysics, and plasma physics.
