Stellar, substellar, and planetary atmosphere models are all highly sensitive to the input opacities. Generational differences between various state-of-the-art stellar/planetary models arise primarily because of incomplete and outdated atomic/molecular line lists. Here we present a database of precomputed absorption cross sections for all isotopologues of key atmospheric molecules relevant to late-type stellar, brown dwarf, and planetary atmospheres: MgH, AlH, CaH, TiH, CrH, FeH, SiO, TiO, VO, and H₂O. The pressure and temperature ranges of the computed opacities are 10⁻⁶–3000 bar and 75–4000 K, and their spectral ranges are 0.25–330 μm for many cases where possible. For cases with no pressure-broadening data, we use collision theory to bridge the gap. We also probe the effect of absorption cross sections calculated from different line lists in the context of ultrahot Jupiter and M-dwarf atmospheres. Using 1D self-consistent radiative–convective thermochemical equilibrium models, we report significant variations in the theoretical spectra and thermal profiles of substellar atmospheres. With a 2000 K representative ultrahot Jupiter, we report variations of up to 320 and 80 ppm in transmission and thermal emission spectra, respectively. For a 3000 K M-dwarf, we find differences of up to 125% in the spectra. We find that the most significant differences arise as a result of the choice of TiO line lists, primarily below 1 μm. In summary, (1) we present a database of precomputed molecular absorption cross sections, and (2) we quantify biases that arise when characterizing substellar/exoplanet atmospheres as a result of differences in the line lists, therefore highlighting the importance of correct and complete opacities for eventual applications to high-precision spectroscopy and photometry.

恒星、亚恒星和行星大气模型都对输入不透明度高度敏感。各种最先进的恒星/行星模型之间的代际差异主要是因为原子/分子线列表不完整和过时。在这里，我们提供了一个与晚型恒星、棕矮星和行星大气相关的关键大气分子的所有同位素的预计算吸收截面数据库：MgH、AlH、CaH、TiH、CrH、FeH、SiO、TiO、VO 和H ₂ O。计算的不透明度的压力和温度范围为 10 ^-6 –3000 bar 和 75-4000 K，它们的光谱范围为 0.25-330 μm 在许多可能的情况下。对于没有压力扩大数据的情况，我们使用碰撞理论来弥合差距。我们还探讨了在超热木星和 M 矮星大气环境中从不同线表计算出的吸收截面的影响。使用一维自洽辐射-对流热化学平衡模型，我们报告了亚恒星大气的理论光谱和热剖面的显着变化。对于 2000 K 具有代表性的超热木星，我们报告的透射和热发射光谱的变化分别高达 320 和 80 ppm。对于 3000 K M 矮星，我们发现光谱差异高达 125%。我们发现最显着的差异是由于 TiO 线列表的选择而产生的，主要低于 1 μ米。总之，(1) 我们提供了一个预先计算的分子吸收截面的数据库，以及 (2) 我们量化了在表征亚恒星/系外行星大气时由于线列表的差异而产生的偏差，因此强调了正确和完整的重要性最终应用于高精度光谱和光度测量的不透明度。