Benchmark test results of a gas-phase simulation. Light solid lines show GGCHEM output. Dash-dotted lines show our output. Both simulations were run at a constant pressure of p = 10⁻⁴ bar, from Τ = 6000 K to Τ = 600 K. The GGCHEM simulation included 120 gas-phase species; our simulation included 40. There were slight differences in the elemental abundance pattern assumed in the two simulations.