I want to run a MD simulation of Mn2+ bound protein but I could not find CHARMM parameters for Mn2+. I came to know that transition metals are highly problematic, as they are typically present as a complex with a different specific geometry depending on the oxidation state and available ligands.
In my system, Mn2+ in complex with Glu, Asp, His, and 2 water molecules. So how can I get Mn2+ CHARMM parameters for my system?
Many thanks for your kind attention.