virtual bool SetRxnRole(unsigned int role)
Set the reaction role of an atom in a reaction molecule/transform.
The set of unsigned integer values for this property is defined by the
OERxnRole namespace. The default value is zero,
OERxnRole::None, which means that the atom does have a role,
i.e. is part of a normal molecule. Other values include
OERxnRole::Reactant, OERxnRole::Agent and
OERxnRole::Product which correspond to reactant, agent and product
atoms in a reaction or transform. The reaction role property may be
retrieved using the OEAtomBase::SetRxnRole method.