Rotational energy levels, transition frequencies and Einstein A coefficients are from CDMS and cover levels up to J=21. In the case of HCO⁺, the spectroscopy is CDMS version 2 (October 2007); in the case of DCO⁺, it is CDMS version 3 (October 2009).

Collisional rates with H₂ are from Denis-Alpizar et al (2020) and cover temperatures in the range from 10 to 200 K.

In the case of HCO⁺, the collision rates are ortho/para resolved; in the case of DCO⁺, only para-H₂ rates were calculated.