to at least Zn for a general implementation within Cloudy. Unfortunately, detailed collisional-radiative modeling data with state-of-the-art DR data is still rather limited. However, extensive tables of effective recombination rate coefficients have been computed by [@summersRAL] for a wide variety of isoelectronic sequences, charge-states, temperatures, and densities. The treatment of DR there is somewhat simplified, but we only require the [*ratio*]{} of finite- to zero-density rate coefficients to determine the suppression factor. We then combine this ratio with our state-of-the-art zero density DR rate coefficients again for use within Cloudy. This ratio is much less sensitive to the specific treatment of DR.

The rather simplistic scaling formula in Eq. \[eqxa\] was found to be inadequate when applied to the extensive tabulation of suppression factors found in [@summersRAL]. Instead, in order to fit the data accurately, a more generalized formula was arrived at, where a pseudo-Gaussian, corresponding to $\mu=0$ in Eq. \[eqsuppression\], was more appropriate, $$S^N(x;q,T) = \left\{
    \begin{matrix}
    1  &  x \le  x_a(q,T,N)\\
    {\rm e}^{-(\frac{x-x_a(q,T,N)}{w/\sqrt{\ln 2}})^{2}}  &  x \geq x_a(q,T,N)
    \end{matrix}\right. \ .
    \label{eqsuppression2}$$ Furthermore, the activation density was found to be best represented by the function $$\begin{aligned}
x_a(q,T,N) & = & x_{a}^{0} + log_{10}\left[\left(\frac{q}{q_0(q,N)}\right)^{7}\left(\frac{T}{T_0(q,N)}\right)^{1/2}\right]\ , \label{eqxanew}\end{aligned}$$ where the variables 