Figure 5: Room temperature Raman spectra for phenanthrene and A₃phenanthrene.

The black arrows point to the major Raman modes with the wavelength of 1,524 cm⁻¹, 1441 cm⁻¹, 1,350 cm⁻¹, 1,037 cm⁻¹, 830 cm⁻¹, 411 cm⁻¹ and 250 cm⁻¹, respectively, and obvious downshift can be observed for these modes. A strong mode at 771 cm⁻¹ in pure phenanthrene becomes invisible with the potassium and rubidium intercalation.