Infrared diagnostics of the solar magnetic field with Mg I 12 μm lines: forward-model results Xin Li, Yongliang Song, H. Uitenbroek, Xiao Yang, Xianyong Bai and Yuanyong Deng A&A, 646 (2021) A79 Published online: 10 February 2021 DOI: 10.1051/0004-6361/202039365