A molecular beam optical/Stark study of calcium monomethyl

Optical and optical Stark spectra of the 0₀⁰ òE-X̃²A₁ band system of a supersonic molecular beam sample of calcium monomethyl, CaCH₃, have been recorded. Field free spectroscopic parameters were obtained on fitting the (|K_R′| = 1, |K′|=0 and 2)-(|K_R″| = 1) and the (|K_R′| = 0, |K′|=1)-(|K_RPrime;| = 0) subbands. The branch features were reassigned and a resulting new set of spectroscopic parameters determined. The value of the a-principal axis component of the spin-rotation parameter, ε_aa(òE), is now consistent with the assumed nature of the low-lying excited electronic states, Dipole moments of 2.62±0.03 D and 1.69±0.02 D were determined for the X̃²A₁ and òE states, respectively. A simple electrostatic model was adapted to predict dipole moments for CaCH₃ and MgCH₃.