Hydrogen Compounds
| H2 | HD | H3+ | H2D+ |
Hydrogen and Carbon Compounds
| CH | CH+ | C2 | CH2 | C2H | *C3 |
| CH3 | C2H2 | C3H(lin) | c-C3H | *CH4 | C4 |
| c-C3H2 | H2CCC(lin) | C4H | *C5 | *C2H4 | C5H |
| H2C4(lin) | *HC4H | CH3C2H | C6H | *HC6H | H2C6 |
| *C7H | CH3C4H | CH3C6H | C8H | *C6H6 |
Hydrogen, Carbon (possibly) and Oxygen Compounds
| OH | CO | CO+ | H2O | HCO | HCO+ |
| HOC+ | C2O | CO2 | H3O+ | HOCO+ | H2CO |
| C3O | CH2CO | HCOOH | H2COH+ | CH3OH | CH2CHO |
| CH2CHOH | CH2CHCHO | HC2CHO | C5O | CH3CHO | c-C2H4O |
| c-C3H2O | CH3OCHO | CH2OHCHO | CH3COOH | CH3OCH3 | CH3CH2OH |
| CH3CH2CHO | (CH3)2CO | HOCH2CH2OH | C2H5OCH3 | (CH2OH)2CO? |
Hydrogen, Carbon (possibly) and Nitrogen Compounds
| NH | CN | N2 | NH2 | HCN | HNC |
| N2H+ | NH3 | HCNH+ | H2CN | HCCN | C3N |
| CH2CN | CH2NH | HC2CN | HC2NC | NH2CN | C3NH |
| CH3CN | CH3NC | HC3NH+ | *HC4N | C5N | CH3NH2 |
| CH2CHCN | CH3CONH2 | HC5N | CH3C3N | CH2CCHCN | CH3CH2CN |
| HC7N | CH3C5N? | HC9N | HC11N |
Hydrogen, Carbon (possibly), Nitrogen and Oxygen
Compounds
| NO | HNO | N2O | HNCO | NH2CHO |
Other Species
| SH | CS | SO | SO+ | NS | SiH |
| *SiC | SiN | SiO | SiS | HCl | *NaCl |
| *AlCl | *KCl | HF | *AlF | *CP | PN |
| H2S | C2S | SO2 | OCS | HCS+ | c-SiC2 |
| *SiCN | *SiNC | *NaCN | *MgCN | *MgNC | *AlNC |
| H2CS | HNCS | C3S | c-SiC3 | *SiH4 | *SiC4 |
| CH3SH | C5S | FeO |
- Species in Italic have been detected by electronic absorption (visible or UV). When they have also been detected in radio, they are underligned.
- Molecular ions are in bold face.
- * circumstellar species
- (c) means cycles, (lin) linear molecules