Number of ions as a function of reaction time in a simulation mimicking the D₃⁺ + H₂ experiment, where the gas initially only consists of D₃⁺ and H₂. The results are shown for simulations run at 15 (left) and 50 K (right). The solid lines represent simulations using the averaged rate coefficients, and the markers represent a simulation where spin states have been explicitly included, but summed over afterward.