KCs分子$c^3Σ^+$态的傅里叶变换光谱和相对论电子结构计算
Fourier-transform spectroscopy and relativistic electronic structure calculation on the $c^3Σ^+$ state of KCs
AI总结：
本文利用傅里叶变换光谱技术测量了KCs分子$c^3Σ^+$态的激光诱导荧光光谱，结合全相对论耦合簇计算进行了势能重构和跃迁特性分析，证实了先前的振动归属。
摘要：
使用在13800 - 11800 cm$^{-1}$范围内运行的Ti:Sapphire激光器，将KCs分子从基态$X^1Σ^+$直接激发至$c^3Σ^+$态。利用傅里叶变换光谱仪记录了$c^3Σ^+ \rightarrow a^3Σ^+$跃迁的激光诱导荧光（LIF）光谱，范围在8000至10000 cm$^{-1}$之间。共确定了673个属于$^{39}$KCs的$c^3Σ^+(Ω=1^{\pm})$态$e/f$分量的旋转振动态项值，涵盖振动能级$v$ = 0至约45，转动能级$J\in [11,149]$，精度约为0.01 cm$^{-1}$；其中包含7个$^{41}$KCs的值。$v\in [0,22]$的实验项值被用于$c^3Σ^+(Ω=1^{\pm})$态的直接逐点势能重构，该重构考虑了由与附近$c^3Σ^+(Ω=0^-)$态的自旋-转动相互作用引起的$Ω$双分裂效应。$B^1Π$、$c^3Σ^+$和$b^3Π$态的势能曲线，以及自旋禁戒的$c-X$和自旋允许的$c-a$跃迁偶极矩的全相对论耦合簇计算，为分析和解释提供了支持；计算了辐射寿命和振动电子分支比。将振动$c-a$ LIF级数中测得的相对强度分布与其理论对应值进行比较，明确证实了[J. Szczepkovski, et. al., JQSRT, 204, 133-137 (2018)]中建议的振动归属。
英文摘要：
The Ti:Saphire laser operated within 13800 - 11800 cm$^{-1}$ range was used to excite the $c^3Σ^+$ state of KCs molecule directly from the ground $X^1Σ^+$ state. The laser-induced fluorescence (LIF) spectra of the $c^3Σ^+ \rightarrow a^3Σ^+$ transition were recorded with Fourier-transform spectrometer within 8000 to 10000 cm$^{-1}$ range. Overall 673 rovibronic term values belonging to both $e/f$-components of the $c^3Σ^+(Ω=1^{\pm})$ state of $^{39}$KCs, covering vibrational levels from $v$ = 0 to about 45, and rotational levels $J\in [11,149]$ were determined with the accuracy of about 0.01 cm$^{-1}$; among them 7 values for $^{41}$KCs. The experimental term values with $v\in [0,22]$ were involved in a direct point-wise potential reconstruction for the $c^3Σ^+(Ω=1^{\pm})$ state, which takes into account the $Ω$-doubling effect caused by the spin-rotational interaction with the nearby $c^3Σ^+(Ω=0^-)$ state. The analysis and interpretation were facilitated by the fully-relativistic coupled cluster calculation of the potential energy curves for the $B^1Π$, $c^3Σ^+$, and $b^3Π$ states, as well as of spin-forbidden $c-X$ and spin-allowed $c-a$ transition dipole moments; radiative lifetimes and vibronic branching ratios were calculated. A comparison of relative intensity distributions measured in vibrational $c-a$ LIF progressions with their theoretical counterparts unambiguously confirms the vibrational assignment suggested in [\emph{J. Szczepkovski, et. al.}, JQSRT, \textbf{204}, 133-137 (2018)].
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
