We study the formation of C$_{18}$H and C$_{18}$H$_2$ by irradiating a cyclo[$18$]carbon molecule with atomic and molecular hydrogen at impact energy, $E$, in the range of 0.5-25 eV. We utilize the density-functional tight-binding method to perform molecular dynamics simulations to emulate the interaction of a carbon ring when colliding with atomic or molecular hydrogen. From our results, the formation of the C$_{18}$H molecules is likely to occur upon irradiating by H atoms at $E < 10$ eV and by H$_2$ molecules at $2 < E < 15$ eV center of mass energy. Formation of C$_{18}$H$_2$ molecules is only observed at around $E = 2$ eV. Our results show that the absorption of hydrogen is more prone in atomic than in molecular hydrogen atmosphere. Thus, we find that the probability of physio-absorption reaches up to 80 \% for atomic projectiles with $E < 5$ eV but only up to 10 \% for the molecular ones. Our analysis shows that the deformation of the carbon ring due to the hydrogen bonding produces transition from $sp$ to $sp^2$ hybridization. The angle between the carbon atoms at the locations near to the H bond in the resulting ring is not 120$^o$ but instead 110$^o$ degrees. No molecular fragmentation of the C$_{18}$ ring is observed.

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原子和分子氢低能辐照形成C18H和C18H2分子的理论研究

我们研究了 C$_{18}$H 和 C$_{18}$H$_2$ 的形成，方法是用原子和分子氢以冲击能 $E$ 照射环 [$18$] 碳分子，在范围为 0.5-25 eV。我们利用密度泛函紧束缚方法进行分子动力学模拟，以模拟碳环与原子或分子氢碰撞时的相互作用。从我们的结果来看，C$_{18}$H 分子的形成很可能发生在被 $E < 10$ eV 的 H 原子和 $2 < E < 15$ eV 的 H$_2$ 分子照射时质量能量。C$_{18}$H$_2$ 分子的形成仅在 $E = 2$ eV 附近观察到。我们的结果表明，氢的吸收在原子气氛中比在分子氢气氛中更容易。因此，我们发现，对于 $E < 5 $ eV 的原子弹，物理吸收的概率高达 80 \%，而对于分子弹，物理吸收的概率高达 10 \%。我们的分析表明，由于氢键导致的碳环变形产生了从 $sp$ 到 $sp^2$ 杂化的转变。所得环中靠近 H 键位置的碳原子之间的角度不是 120$^o$，而是 110$^o$ 度。没有观察到 C$_{18}$ 环的分子碎片。