Combined model for 15N, 13C, and spin-state chemistry in molecular clouds O. Sipilä, L. Colzi, E. Roueff, P. Caselli, F. Fontani and E. Wirström A&A, 678 (2023) A120 Published online: 13 October 2023 DOI: 10.1051/0004-6361/202347106