First-principles molecular dynamics simulations of the interaction of ionic projectiles with liquid water and ice
First-principles molecular dynamics simulations of the interaction of ionic projectiles with liquid water and ice
复制标题
离子射弹与液态水和冰相互作用的第一原理分子动力学模拟
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
E. Artacho
中科院分区：
文献类型：
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作者：
J. Kohanoff;E. Artacho
我们首先介绍了碳射弹在绝热状态下通过液态水的第一性原理分子动力学模拟结果，其中电子总是处于瞬时基态。我们研究了一系列的弹丸速度估计上限的绝热近似和分析不同类型的碰撞事件。我们发现，对于高弹丸速度的碰撞大多是二进制的，但在较低的速度大多数轨迹表现出连续的能量损失的介质，这不能被正确地描述为一个序列的独立的二进制碰撞。对于最慢的射弹，我们观察到新的化学物种，如水合氢，H5O2+和过氧化氢的形成。当碳原子完全停止时，我们也会看到甲酸等物质的形成。通过分析次级碎片的产生，我们观察到，这些主要是超热的，它们的空间产生率随着温度的降低而增加。
We first present results of first‐principles molecular dynamics simulations of the passage of Carbon projectiles through water in the liquid state in the adiabatic regime, where the electrons are always in the instantaneous ground state. We study a range of projectile velocities up to the estimated upper limit for the adiabatic approximation and analyze the different types of collision events. We show that for high projectile velocities collisions are mostly binary, but at lower velocities most trajectories exhibit a continuous energy loss to the medium, which cannot be properly described as a sequence of independent binary collisions. For the slowest projectiles we observe the formation of new chemical species such as hydronium, H5O2+ and hydrogen peroxide. When C‐atoms are completely stopped, then we also see the formation of species like formic acid. By analyzing the generation of secondary fragments, we observe that these are mostly hyperthermal and their spatial rate of generation increases with decr...