SEARCH Articles Figures Tables Coupled cluster first-order Coupling constant first-order Coupling constant measuring first-order spectra First-Order Spin-Orbit Coupling First-Order Spin-Orbit Coupling Selection Rules First-order expansion of the coupling work First-order-reaction coupling Measuring coupling constants from first-order spectra Non-First-Order Splitting Patterns Strong Coupling Order coupling Some spin-coupling effects (first-order) Vibronic coupling first order