Vertical equilibrium excitation energies (eV) and equilibrium positions (Å) for the ground state and first two excited states of the ionic target

Table 1. Vertical equilibrium excitation energies (eV) and equilibrium positions (Å) for the ground state and first two excited states of the ionic target. Abstract Potential energy curves for electronically excited states of molecular nitrogen are calculated using three different ab initio procedures. The most comprehensive of these involves the use of scattering calculations, performed at negative energy using the UK molecular R-matrix method. Such calculations are used to characterize all the Rydberg states of N2 with n ≤ 6 and ℓ ≤ 4 as well as many higher states including some Rydberg states associated with the first excited A 2Πu state of N_2^+. Many of these states are previously unknown. The calculations are performed at a dense grid of internuclear separations allowing the many avoided crossings present in the system to be mapped out in detail. Extensive comparisons are made with the previously available data for excited states of N2.

表1. 离子靶基态及前两个激发态的垂直平衡激发能（单位：电子伏特，eV）与平衡位置（单位：埃，Å）。摘要：本研究采用三种不同的从头算（ab initio）方法，计算了分子氮（N₂）的电子激发态势能曲线。其中最全面的一种方法借助英国分子R矩阵（UK molecular R-matrix）方法，在负能区间开展散射计算。此类计算可表征主量子数n≤6、角量子数ℓ≤4的所有N₂里德伯（Rydberg）态，以及诸多更高能态，其中包括与一价氮离子（N₂⁺）首个激发态A ²Π_u相关的部分里德伯态。上述多数能态在此前尚未被发现。本计算在密集的核间距网格上开展，可详细绘制出体系中存在的诸多避交叉轨迹。研究中将计算结果与已公开的N₂激发态相关数据进行了充分比对。