From McQuarrie & Simon “Physical Chemistry – A Molecular Approach”

From W. Demtröder “Molecular Physics”

Basic QM and Nomenclature for Electronic States of Linear Molecules Nodal structure gives rise to three quantum numbers: n-1 = total number of nodal planes ℓ = number of nodal planes in  and   = number of nodal planes in  0 ≤  ≤ ℓ ≤ n-1 Cylindrical symmetry, so ℓ is not a good quantum number anymore, but mℓ is Energy depends on mℓ2, not mℓ, so states with ±mℓ are degenerate, use  = |mℓ| to describe unique energy Notation for 1-e—orbitals: , , , , .... for  = 0,1,2,3,... Parity (for molecules with inversion symmetry only) g/u subscript Molecular orbitals denoted g/u Spin z-projection is a good quantum number: ms =  = ±1/2 Fine structure splitting in 1-e—systems (in analogy to atoms): Vℓ,s = A··ms