Section \[sec:cross\] we discuss the experimental data sources and semiempirical fitting formulae used for our EIMI cross sections. Section \[sec:csd\] briefly reviews the relation between the cross sections and the CSD. In Section \[sec:equilib\] we present our ionization-equilibrium calculations and compare them to calculations that consider only electron-impact single ionization (EISI). Section \[sec:dynamic\] explores the influence of EIMI on the CSD in situations where the temperature varies rapidly. Our conclusions are summarized in Section \[sec:conclusions\].

Electron-Impact Multiple-Ionization Cross Sections {#sec:cross}
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EIMI involves the ejection of two or more electrons from an ion following a single collision. There are a number of specific processes leading to multiple ionization, many of which are analogous to those for EISI [@Muller:Book:2008]. A collision can result in direct ionization of two or more electrons starting at the multiple-ionization threshold, which depends on the number of electrons to be removed. Excitation-multiple-autoionization (EMA) occurs when an electron excites an electron in the target to a level that decays by ejecting two or more electrons. For highly charged ions, the dominant multiple-ionization process is often ionization-autoionization (IA), in which a collision directly ionizes a core electron and additional electrons are released when system relaxes to fill the 