The thallium hydride (TIH) is one of the most promising standard test molecular systems containing heavy-elements of relativistic quantum mechanical techniques. Here, we have investigated the low-lying electronic states in TlH using the multireference configuration interaction method including the core-valence correlations and spin-orbit coupling effects. The ground and excited electronic states of the TlH molecule as well as transition properties are computed and characterized. The computed spectroscopic constants of the bound states are in good agreement with the available experiments. The transition dipole moments and Franck-Condon factors for a³Π-X¹Σ⁺ are obtained. The spontaneous radiative lifetime of a³Π₀₊(v′=0) is estimated to be 357 µs. The present results may be helpful for the future spectroscopic measurements of the TlH molecule.

氢化th（TIH）是最有前途的标准测试分子系统之一，其中包含相对论量子力学技术的重元素。在这里，我们使用包括核价相关性和自旋轨道耦合效应在内的多参考构型相互作用方法研究了TlH中的低电子态。计算并表征了T1H分子的基态和激发态电子态以及跃迁性质。束缚态的计算光谱常数与可用的实验非常吻合。跃迁偶极矩和弗兰克- Condon因子为一个³ -XΠ ¹ Σ ⁺获得。的自发辐射寿命一个³Π ₀₊（v '= 0），估计是357微秒。目前的结果可能对T1H分子的未来光谱测量有帮助。