| Carrier | Type of transitions | Ref. |
| Neutral atoms and first ions (13 elements) | bound-free and line transitions | 1 |
| Positive ions | free-free (bremsstrahlung) | 2 |
| H- | bound-free and free-free | 3, 4, 5 |
| H2-, He-, C- | free-free | 6, 7, 8 |
| H2O, CO2, HCN, C2H2, H2S, SO2, OCS | rotational, ro-vibrational including overtones and combination bands | App. A |
| CO, SiO, CS | rotational, ro-vibrational including first and second overtone | App. A |
| CN, OH, CH, SO, HS, SiS, SiN, SiC | rotational and fundamental mode ro-vibrational | 5 |
| C2H, C2N | rotational | 5 |
| H2, N2 | ro-vibrational (quadrupole) | App. A |
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(1) Woitke & Sedlmayr (1999) and references therein;
(2) Hummer (1988);
(3) Wishart (1979);
(4) Stilley & Callaway (1970); (5) Paper I and references therein; (6) Somerville (1964); (7) John (1994); (8) John & Williams (1977). |