A massive search for chemical routes leading to methanol formation in gas phase has been conducted using computational chemistry, at the CBS-QB3 level of theory. The calculations were performed at five different temperatures (100, 80, 50, 20, and 10 K) and at three pressures (0.1, 0.01, and 0.001 atm) for each temperature. The search was focused on identifying reactions with the necessary features to be viable in the interstellar medium (ISM). A searching strategy was applied to that purpose, which allowed to reduce an initial set of 678 possible reactions to a subset of 11 chemical routes that are recommended, for the first time, as potential candidates for contributing to methanol formation in the gas phase of the ISM. They are all barrier-less, and thus they are expected to take place at collision rates. Hopefully, including these reactions in the currently available models, for the gas-phase methanol formation in the ISM, would help improving the predicted fractional abundance of this molecule in dark clouds. Further investigations, especially those dealing with grain chemistry and electronic excited states, would be crucial to get a complete picture of the methanol formation in the ISM.

中文翻译：

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系统搜索星际空间中气相化学反应对甲醇形成的贡献

在理论上CBS-QB3的水平上，已经使用计算化学方法对导致气相形成甲醇的化学路线进行了大规模研究。对于每个温度，在五个不同的温度（100、80、50、20和10 K）和三个压力（0.1、0.01和0.001 atm）下进行计算。搜索的重点是确定具有在星际介质（ISM）中可行的必要特征的反应。为此，采用了一种搜索策略，该方法允许将最初的678种可能的反应减少到11条化学路线的子集，这是首次推荐，作为可能有助于在甲醇气相中形成甲醇的潜在候选物。主义。它们都是无障碍的，因此预计它们将以碰撞速度发生。希望，包括ISM模型中气相甲醇形成的当前可用模型中的这些反应，将有助于改善该分子在乌云中的预测分数丰度。进一步研究，尤其是那些涉及晶粒化学和电子激发态的研究，对于全面了解ISM中甲醇的形成至关重要。