All of the chemical species and reaction in a WACCM case will be listed in the following 2 files under your case directory in the sub-directory CaseDocs: chem_mech.in and chem_mech.doc.These files are also available in the source code for each chemistry that is available out of the box. For example, if you are using CESM2(WACCM6), the standard configuration uses TSMLT chemistry (troposphere, stratosphere, mesosphere, lower thermosphere) with MAM4 aerosols. The chemistry files are found here:$srcdir/components/cam/src/chemistry/pp_waccm_tsmlt_mam4We do not have any iodine chemistry in WACCM at this time.