The photodissociation of methanol, which is an important radical source on interstellar ices, was studied using quantum chemistry calculations. Surface hopping simulations using the time-dependent density functional theory were performed, and the potential energy curves of the low-lying excited states were analyzed using the second-order multireference perturbation theory to reveal the reaction mechanism in the gas phase. We showed that the generation of CH₃O would more frequently occur than that of CH₂OH on the S₁ state in contrast to the ground state. We also discuss why the ratio of CH₃O and CH₂OH differs between the gas and solid phases.

中文翻译：

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甲醇光解反应的理论研究

使用量子化学计算研究了甲醇的光解离，甲醇是星际冰上的重要自由基来源。进行了基于时变密度泛函理论的表面跳跃模拟，并利用二阶多参考扰动理论分析了低激发态的势能曲线，揭示了气相中的反应机理。我们表明，与基态相比，在S ₁状态下，CH ₃ O的生成比CH ₂ OH的生成更为频繁。我们还讨论了为什么气相和固相之间CH ₃ O和CH ₂ OH的比例不同。