Neutral and ionic N species exhibit a rich spectrum as a result of the large density of couplings between states with different multiplicities. In this sense, spectra of the molecular ion N are investigated combining Fourier transform spectroscopy and methods. We have reanalyzed the First Negative band System (B X) including five bands not reported previously by Fourier spectroscopy. The spectra were recorded using a resolution of 0.6 cm and accuracy of 0.005 cm. These results are then compared with new MRCI+Q/AV6Z calculations. For the first time, transition probabilities are computed for the previously observed 2-A band system. The 2 state ( = 67,029 cm) has a dissociation energy of 24,787 cm at = 2.7332 a. The predicted lifetimes for the 2-A emissions are of the order of 170 ns. The calculated transition probabilities A(=0, =0) for the B-X and 2-A bands are 1.156 × 10 and 1.716 × 10 s, respectively. The role of spin–orbit (SO) matrix elements in the spectroscopic data of N is discussed, including results for SO constants as a function of vibrational level of A state. Our theoretical SO constant A(A) = −73.40 cm reproduces well the experimental one (−74.67 cm). SO calculations are also used to investigate spin-forbidden transitions on N. The obtained 30 cm. Following a sum-over-states (SOS) methodology, the best estimate for the spin-rotation constant of the X and B states are 0.0096 and 0.0211 cm, respectively, in quantitative agreement with the present experimental data of 0.00917(36) and 0.0206(9).

中文翻译：

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N[公式省略]电子跃迁的新视角：实验和理论研究

由于不同多重态之间的高耦合密度，中性和离子氮物种表现出丰富的光谱。从这个意义上说，结合傅里叶变换光谱和方法来研究分子离子N的光谱。我们重新分析了第一负带系统（BX），包括傅立叶光谱先前未报告的五个带。使用 0.6 cm 的分辨率和 0.005 cm 的精度记录光谱。然后将这些结果与新的 MRCI+Q/AV6Z 计算结果进行比较。首次计算了先前观察到的 2-A 能带系统的跃迁概率。 2 态 (= 67,029 cm) 在 = 2.7332 a 时的解离能为 24,787 cm。 2-A 发射的预计寿命约为 170 ns。计算得出的 BX 和 2-A 频段的转移概率 A(=0, =0) 分别为 1.156 × 10 和 1.716 × 10 s。讨论了自旋轨道 (SO) 矩阵元素在 N 光谱数据中的作用，包括 SO 常数作为 A 态振动能级函数的结果。我们的理论 SO 常数 A(A) = −73.40 cm 很好地再现了实验常数 (−74.67 cm)。 SO 计算还用于研究 N 上的自旋禁止跃迁。获得的 30 cm。根据状态求和（SOS）方法，X和B态的自旋旋转常数的最佳估计分别为0.0096和0.0211 cm，与目前的实验数据0.00917（36）和0.0206定量一致（9）。