Band 6 and band 7 average spectra of the inner of the central region. (a) HCN 3–2, HC₃N ν₇ = 2, CH₂NH; (b) HCO⁺ 3–2, and HCN-VIB 3–2; (c) CS 7–6 with a vibrational line of CO also marked; (d) HC¹⁵N 4–3; (e) HCN 4–3, HC₃N 39–38, HC₃N ν₇ = 1; (f) HCO⁺ 4–3, HCN-VIB 4–3, and HC₃N ν₇ = 2. The dashed lines mark ν_sys (cz = 3880 km s⁻¹) of the various species. We also indicate ±100 km s⁻¹ velocities for several of the species.