CMAQ-Hg aqueous chemistry

Hi everyone,
I use CMAQ-5.3.1 for simulating Hg and use acm_ae6_mp cloud module. There is an aqueous reaction:
Reduction of all Hg(II) species by oxalate RXN 6
Hg(II) + R(CO2)2 => Hg+ + products
Hg+ + HORCO2 => Hg(aq) + products
i read several papers and they all say there are reduction reaction of Hg ii by dicarboxylic acids. So I wonder if the first reaction is reduction of Hg II by dicarboxylic acids. Also, are all the aqueous species in AQ_DATA.F file? If so, why i cannot find species of this kind (R(CO2)2) in that file. I also checked hlconst.F. No such species either.

This is a parameterization of divalent Hg reduction by dicarboxylic acid. For details please see Bash et al 2014. This is an older parameterization for the ae6 mechanism and is likely due for an update for ae7 and more recent findings.

Take care,