coefficients by developing a suppression factor model, which was motivated by the early work of @badnell for and extended to all other ions using physically-motivated scaling considerations, and more precise fitting of collisional-radiative data [@summersRAL]. Accurate zero-density DR rate coefficients were then multiplied by this suppression factor and introduced into Cloudy to study the finite-density effects on computed ionization balances of both collisionally ionized and photoionized plasmas. It is found that the difference in ionization balance between the near-zero and finite-density cases is substantial, and thus there is sufficient justification for further studies of collisional suppression from generalized collisional-radiative calculations. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

The present results are intended to be preliminary, and to demonstrate the importance of density effects on dielectronic recombination in astrophysical plasmas. Given the approximations adopted, we suggest that their incorporation into models (e.g., via Cloudy) be used with a little caution. For example, one might run models with and without the effects of suppression at finite density, especially in modeling higher density plasmas 