Two-photon vibronic transitions in crystalline chrysene
CHEMICAL PHYSICS(1990)
摘要
The two-photon (TP) absorption spectrum of crystalline chrysene has been measured at 10 K in the wavelength region 370–300 nm. Vibronic transitions to the first excited level L b (B u ) are observed due to b u vibrations of CC stretching character. Evidence of strong crystal field effects on electronic levels is found in our spectrum. The energy splitting between the two crystal origins is estimated to be ≈ 400 cm −1 in good agreement with previous observations. The TP absorption spectrum is accordingly discussed in terms of crystal, rather than molecular, states. Calculation of vibronic coupling coefficients for all b u vibrational modes with frequency < 1700 cm −1 by means of the orbital following method helps identifying the most active b u modes in the vibronic structure of the L b (B u ) state. Application of the oriented-gas model on calculated TP tensors shows that b u vibrations induce intensity for both crystal origins, in good agreement with experimental results. Vibronic coupling is also responsible for TP absorption in the first excited A g state, 2A g .
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要