The Franck-Condon Principle · Why Electronic Transitions Are Vertical
unseel.com · vertical transition · vibronic overlap · Stokes shift
state ground X ¹Σ
lands on v′ = 0
FC factor |⟨χ′|χ″⟩|²
step
ground surface X
excited surface B (displaced)
vertical transition (photon)
vibrational overlap / progression
Unseel.com · Franck-Condon Principle Unseel.com · The Franck-Condon Principle — Concepts