Methylidyne ion

Rotational energy levels, transition frequencies and Einstein A coefficients up to J=13 (2500 cm-1) are from CDMS, version 2 of April 2010.

Collisional rates with H2 are scaled He rates from Turpin et al (2010), calculated for temperatures in the range from 10 to 200 K for energy levels up to J=5.

Collisional rates with H atoms and electrons are from Faure et al (2017) and cover temperatures from 10 to 3000 K for levels up to J=13.

Last update: 2022 August 5. Send comments to