Brooke James S A, Bernath Peter F, Western Colin M, van Hemert Marc C, Groenenboom Gerrit C
Department of Chemistry, University of York, York YO10 5DD, United Kingdom.
School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom.
J Chem Phys. 2014 Aug 7;141(5):054310. doi: 10.1063/1.4891468.
A new line list for rovibrational and rotational transitions, including fine structure, within the NH X³Σ⁻ ground state has been created. It contains line intensities in the form of Einstein A and f-values, for all possible bands up to v' = 6, and for J up to between 25 and 44. The intensities are based on a new dipole moment function (DMF), which has been calculated using the internally contracted multi-reference configuration interaction method with an aug-cc-pV6Z basis set. The programs RKR1, LEVEL, and PGOPHER were used to calculate line positions and intensities using the most recent spectroscopic line position observations and the new DMF, including the rotational dependence on the matrix elements. The Hund's case (b) matrix elements from the LEVEL output (available as Supplement 1 of the supplementary material) have been transformed to the case (a) form required by PGOPHER. New relative intensities for the (1,0) band have been measured, and the calculated and observed Herman-Wallis effects are compared, showing good agreement. The line list (see Supplement 5 of the supplementary material) will be useful for the study of NH in astronomy, cold and ultracold molecular systems, and in the nitrogen chemistry of combustion.
已创建了一份新的线列表，用于描述NH X³Σ⁻基态内的振转跃迁，包括精细结构。它包含了直至v' = 6以及J直至25到44之间所有可能谱带的以爱因斯坦A和f值形式表示的谱线强度。这些强度基于一个新的偶极矩函数（DMF），该函数是使用内收缩多参考组态相互作用方法并结合aug-cc-pV6Z基组计算得出的。利用程序RKR1、LEVEL和PGOPHER，根据最新的光谱线位置观测结果和新的DMF来计算谱线位置和强度，其中包括矩阵元的转动依赖性。来自LEVEL输出（可作为补充材料的补充1获取）的洪德情况（b）矩阵元已转换为PGOPHER所需的情况（a）形式。已测量了（1,0）带的新相对强度，并比较了计算得到的和观测到的赫尔曼 - 沃利斯效应，结果显示吻合良好。该线列表（见补充材料的补充5）将有助于研究天文学中的NH、冷和超冷分子系统以及燃烧中的氮化学。
