## Resolved dielectronic recombination coefficients

The data sets are collections of state-selective dielectronic recombination coefficients of Maxwellian free electrons. The process occurs via a radiative stabilisation of a doubly excited state formed by resonance capture, in competition with Auger breakup, and is represented by the reactions: $X_{\rho}^{\left( z+1\right) +} + {\rm e}^- \leftrightarrow X_{i,nl}^{z+} \rightarrow X_{\sigma,nl}^{z+} + h\nu$

Non-resonant free electron capture (radiative recombination) is treated as a separate independent process (see ADF08). The coefficients are resolved by initial parent metastable $\rho$, final parent metastable core $\sigma$ and captured electron $nl-$shell. Capture into low nl-shells is further resolved into terms or levels. The data sets are normally grouped in sub-directories for different iso-electronic sequences (of the initial ion). There are data sets both for term (LS) and intermediate (IC) coupling. Individual data sets are also separated by the type of parent transition ($\rho \rightarrow i$) according to the valence n-shell to which $\rho$ and $i$ belong. The data sets are tabulated as a function of electron temperature and the data are blocked for capture to resolved low levels (LS or IC), to high nl-shells (in the IC case) and to very high n-shells (LS and IC cases), depending on survival against secondary Auger breakup. The data sets span a wide range of elements up to zinc and span currently iso-electronic sequences up to Mg-like. These are complex data sets and the user is advised to read the detailed specification of ADF09 carefully. See also Badnell et al (2003) for more details on the treatment of dielectronic recombination within ADAS. ADF09 is a fundamental data format. Effective recombination coefficients, including dielectronic recombination, three-body recombination, cascading and re-ionisation losses occur as a derived data output from collisional–radiative modelling and such data are archived as a sub-class of data format ADF11.