On the effective spin-spin constants of some states of diatomic molecules. Application to the co molecule

Abstract

Semi empirical formulas are given for the effective spin-spin constants of some electronic states of diatomic molecules described by a single configuration. These formulas concern both the direct spin-spin part and the isoconfigurational second order spin-orbit part of the effective constants of the (π ²)³ Σ ⁻, (ππ′), (π ³ π′) (π ³ π′³)³ Σ ^±, (π ³ π′)³ Δ, (σπ ²)⁴ Σ ⁻, (πσ), (σπ ³)³ Π and (π ³ π′²)⁴ Π states. Using these expressions, a qualitative agreement between calculated and observed spin-spin constants is found in the case of theα′³ Σ ⁺,e ³ Σ ⁻,α ³ Π andd ³Δ states of the CO molecule and of the$A^3 \Sigma _{u^ + }$ and$B^3 \Sigma _{u^ - }$ states of the O₂ molecule.