Fractional abundances for nitrogen-bearing species with a gas density of 10⁷ cm⁻³ and a fast warm-up. HCN gas (solid lines) and ice (dashed lines) abundances with the color key for all four panels (top left), HC₃ N gas (top right), CH₃CN gas (bottom left), and C₂H₅CN gas (bottom right) abundances over time are shown for four initial HCN ice abundances (0, 0.1, 1, and 10%). The observed abundances (horizontal lines) for G35.20 A are shown for reference.