First-principles lifetime of the four-atom collision complex

For $(\mathrm{NaK})_2$, $(\mathrm{RbCs})_2$ and $\mathrm{KRb} + \mathrm{KRb}$, compute the sticking lifetime $\tau = 2 \pi \hbar \rho / N_o$, with $\rho$ the density of states of the complex at threshold including conserved total angular momentum, parity and nuclear spin, and $N_o$ the number of open channels. Answer: $\tau$ for each system within a factor 2 of measured values, or a quantified failure of statistical theory.

Ab initio density-of-states calculations compared with direct complex-lifetime measurements in light-free traps.