用多重差分的方法， 从双原子分子跃迁谱线的普遍表达式出发， 已经建立起了预言双原子分子P线系高激发振转跃迁谱线的解析物理公式。 采用同样的方法， 充分利用现有实验条件下测定的部分振转跃迁谱线数据， 文章建立了预言双原子分子Q线系高激发振转跃迁谱线的物理公式。 使用该公式和一组经过物理筛选的（15条）精确的实验跃迁谱线， 研究了IrN分子A1Π—X1Σ+跃迁系统中(4,1),(3,1)跃迁带的Q支发射光谱。 结果表明， 该公式不仅很好地重复了所有已知的实验光谱数据， 且正确预言了实验没有获得的很多高转动量子态的未知发射谱线， 从而提供了一种新的预言高转动量子态的未知跃迁谱线的物理方法。

An analytical formula was proposed recently to predict the accurate P-branch spectral lines of rovibrational transitions for diatomic systems by taking multiple spectral differences. A similar analytical expression was suggested here to predict the Q-branch spectral lines of rovibrational transitions. This formula was applied to study the high-lying Q-branch emission spectra of the (4,1) and (3,1) bands of the A1Π—X1Σ+ system of IrN molecule using fifteen known accurate experimental transition data. The results show that not only the known experimental transition lines were reproduced but also the correct values of the unknown spectral lines were predicted.