fix bug: reactants -> rxn.reactants
fix bug: reactants -> rxn.reactants

idem dito for reactants0/products0

chatelak/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,chatelak/RMG-Py,nyee/RMG-Py,pierrelb/RMG-Py