Steimle T C, Chen Jinhai, Gengler Jamie
Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604. USA.
J Chem Phys. 2004 Jul 8;121(2):829-34. doi: 10.1063/1.1759314.
Numerous branch features in the (0,0) A 2Pi-X 2Sigma+ band system of calcium monohydride CaH have been studied by optical Stark spectroscopy. The Stark shifts, Stark splittings, and appearance of electric-field-induced transitions in the high resolution laser-induced fluorescence spectra are analyzed to produce values for the magnitude of the permanent electric dipole moments mid R:micromid R: of 2.94(16) D and 2.372(12) D for the X 2Sigma+(v=0) and A 2Pi(v=0) states, respectively. A comparison with values predicted from a semiempirical electrostatic model and previous ab initio calculations for mid R:micromid R: (X 2Sigma+) is presented. The change in mid R:micromid R: upon excitation from the X 2Sigma+ state to the A 2Pi state is rationalized using a simple molecular orbital description.
利用光学斯塔克光谱对氢化钙（CaH）的（0,0）A²Π - X²Σ⁺能带系统中的众多分支特征进行了研究。分析了高分辨率激光诱导荧光光谱中的斯塔克位移、斯塔克分裂以及电场诱导跃迁的出现情况，得出X²Σ⁺（v = 0）和A²Π（v = 0）态的永久电偶极矩|R|分别为2.94(16) D和2.372(12) D。给出了与半经验静电模型预测值以及先前对|R|（X²Σ⁺）的从头算计算值的比较。利用简单的分子轨道描述解释了从X²Σ⁺态激发到A²Π态时|R|的变化。
