We investigated the reaction of multi-valence (+2) ionization states of water dimer (H₂O)₂ using direct ab initio molecular dynamics method. The following multi-valence ionization states were considered. In the direct two-electron ionization state, (H₂O)₂ was ionized to form (H₂O)₂ ²⁺ in one step; in the stepwise two-electron ionization state, (H₂O)₂ was first converted to (H₂O)₂ ⁺ and further ionized after structural relaxation. The (H₂O)₂ ²⁺ from direct ionization dissociated into two H₂O⁺ ions, while (H₂O)₂ ²⁺ in stepwise ionization generated H₃O⁺ and OH⁺ ions from H₃O⁺–OH radical-ion pairs. Additionally, we performed dynamics calculations for the excited state of (H₂O)₂ ²⁺ generated through direct ionization. The excited (H₂O)₂ ²⁺ ions also dissociated to form H₃O⁺ and OH⁺ ions. The reaction mechanism of multi-valence ionization states of (H₂O)₂ is discussed on the basis of calculation results.

我们使用直接从头算分子动力学方法研究了水二聚体 (H ₂ O) ₂的多价 (+2) 电离态的反应。考虑了以下多价电离状态。在直接二电子电离状态下，(H ₂ O) ₂一步电离形成(H ₂ O) ₂ ²⁺；在逐步双电子电离状态下，(H ₂ O) ₂首先转化为(H ₂ O) ₂ ⁺并在结构弛豫后进一步电离。(H ₂ O) ₂ ²⁺ 从直接电离分解为两个 H ₂ O ⁺离子，而 (H ₂ O) ₂ ²⁺在逐步电离中从 H ₃ O ⁺ –OH 自由基离子对生成 H ₃ O ⁺和 OH ⁺离子。此外，我们对通过直接电离产生的 (H ₂ O) ₂ ²⁺的激发态进行了动力学计算。被激发的 (H ₂ O) ₂ ²⁺离子也离解形成 H ₃ O ⁺和 OH ⁺ 离子。根据计算结果讨论了(H ₂ O) ₂多价电离态的反应机理。