Khalil Malathe, Mahmoud Salman, Brady Ryan P, Almehairbi Mubarak, Gacesa Marko, Yurchenko Sergei N, Tennyson Jonathan, Al Ghaferi Amal, El-Kork Nayla
Department of Mechanical Engineering, Khalifa University, Abu-Dhabi, United Arab Emirates.
Physics Department, Khalifa University, Abu-Dhabi, United Arab Emirates.
Phys Chem Chem Phys. 2025 Jan 29;27(5):2783-2801. doi: 10.1039/d4cp03418j.
The spectrum of carbon monoxide is important for astrophysical media, such as planetary atmospheres, interstellar space, exoplanetary and stellar atmospheres; it also important in plasma physics, laser physics and combustion. Interpreting its spectral signature requires a deep and thorough understanding of its absorption and emission properties. A new accurate spectroscopic model for the ground and electronically-excited states of the CO molecule computed at the aug-cc-pV5Z CASSCF/MRCI+Q level is reported. Detailed investigation of the AΠ-XΣ, BΣ-XΣ, CΣ-XΣ, and EΠ-XΣ band systems is presented consisting of calculated potential energy curves as well as permanent and transition dipole moment curves. The BΣ and CΣ states are characterized by having multiple avoided crossings which are diabatized to obtain an accurate electronic structure model. The results are validated by comparing our computed spectra with various high-resolution spectroscopy experiments. To the best of our knowledge, this is the first systematic theoretical spectroscopic study of highly excited states of the CO molecule.
一氧化碳的光谱对于天体物理介质很重要，例如行星大气、星际空间、系外行星和恒星大气；它在等离子体物理学、激光物理学和燃烧中也很重要。解释其光谱特征需要对其吸收和发射特性有深入透彻的理解。本文报道了一种在aug-cc-pV5Z CASSCF/MRCI+Q水平下计算得到的用于CO分子基态和电子激发态的新的精确光谱模型。文中对AΠ-XΣ、BΣ-XΣ、CΣ-XΣ和EΠ-XΣ能带系统进行了详细研究，包括计算得到的势能曲线以及永久偶极矩和跃迁偶极矩曲线。BΣ和CΣ态的特征是存在多个避免交叉，通过对其进行非绝热处理以获得精确的电子结构模型。通过将我们计算得到的光谱与各种高分辨率光谱实验进行比较，验证了结果。据我们所知，这是对CO分子高激发态的首次系统性理论光谱研究。
