Title: Dissociative electron attachment to the HNC$_3$ molecule Show Chinese title

Title: HNC$_3$分子的离解电子附着

Abstract: Dissociative electron attachment (DEA) to the HNC$_3$ is modeled theoretically using a first-principles approach. In HNC$_3$+$e^-$ collisions, there is a low-energy resonance, which has a repulsive character along the H+NC$_3$ coordinate and becomes a bound electronic state of the HNC$_3^-$ anion near the equilibrium of HNC$_3$. The anion state dissociates without a potential barrier towards C$_3$N$^-$+H. The cross section and the rate coefficient of the process were computed. The obtained rate coefficient at low temperatures is $5\times 10^{-9}$cm$^3$/s at 300~K. Such a value of the DEA rate coefficient makes the DEA process by three orders of magnitude more efficient in producing negative molecular ions in the interstellar space than the radiative electron attachment (REA). It is suggested that negative molecular carbon-chain ions, observed in the interstellar medium, are produced by DEA rather than REA. Show Chinese abstract

Abstract: 解离电子附着（DEA）到HNC$_3$被理论上使用第一性原理方法进行模拟。 在HNC$_3$+$e^-$碰撞中，存在一个低能共振，沿着H+NC$_3$坐标具有排斥特性，并在HNC$_3^-$的平衡位置附近成为HNC$_3$阴离子的束缚电子态。 阴离子状态无势垒地解离为 C$_3$N$^-$+H。 该过程的截面和速率系数已被计算。 在低温下获得的速率系数在300~K时为$5\times 10^{-9}$cm$^3$/s。 这样的 DEA 速率系数使 DEA 过程在星际空间中产生负分子离子的效率比辐射电子附着 (REA) 高三个数量级。 建议在星际介质中观测到的负分子碳链离子是由 DEA 而不是 REA 产生的。