OPTAB: Public code for generating gas opacity tables for radiation hydrodynamics simulations Shigenobu Hirose, Peter Hauschildt, Takashi Minoshima, Kengo Tomida and Takayoshi Sano A&A, 659 (2022) A87 Published online: 10 March 2022 DOI: 10.1051/0004-6361/202141076