Rovibrational and fine structure parameters

Rotational constants, centrifugal distortion constants, rotation-vibration interaction constants, Dunham energy parameters, Dunham potential coefficients, parameters of the breakdown of the Bom-Oppenheimer approximation and of the nuclear field shift, and equilibrium intemuciear distances. Eiectronic spin-rotation, spin-spin, spin-orbit, and /1-doubling parameters and their centrifugai-distortion corrections in excited electronic states 

The rotational sub structure of electronic and rovibrational spectra of a diatomic molecule is mainly characterized by only one moment of inertia or one rotational constant in each of the two participating states. Only one (non-degenerate) vibrational degree of freedom is present. 

We consider in the following the rovibrational parameters of molecules in a (closed-shell) S electronic state, and later the additional parameters necessary to formulate further intramolecular interactions in 2, 2, 11, and A excited electronic states which are important for the present data compilation. 

Tiemann [92Tie, 95Tie] has reviewed the pertinent parameter definitions in his introductions to the diamagnetic and paramagnetic diatomic molecules contained in volumes II/19a and II/19D1 of the Landolt-Bdmstein series. We rely here closely on his formulations and in part on those of Brown and Carrington in their book Rotational Spectroscopy of Diatomic Molecules [03Bro]. 

We choose the so-called representation of the effective fine structure Hamiltonian where the kinetic rotational part is written = B N. Brown and Carrington [03Bro] give reasons for preferring this over 

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