A MOLECULAR-BEAM OPTICAL STARK STUDY OF CALCIUM MONOMETHYL/

Optical and optical Stark spectra of the O-0(0) (A) over tilde (2)E-(X ) over tilde (2)A(1) band system of a supersonic molecular beam sample of calcium monomethyl, CaCH3, have been recorded. Field free spectros copic parameters were obtained on fitting the (/K'(R)/ = 1, /k'/ = 0 a nd 2)-(/K ''(R)/ = 1) and the (/K'(R)/ = 0, /K'/ = 1)-(/K ''(R)/ = 0) subbands. The branch features were reassigned and a resulting new set of spectroscopic parameters determined. The value of the a-principal a xis component of die spin-relation parameter, epsilon(aa)((A) over til de(2)E), is now consistent with the assumed nature of the low-lying ex cited electronic states. Dipole moments of 2.62+/-0.03 D and 1.69+/-0. 02 D were determined for the (X) over tilde (2)A(1), and (A) over tild e(2)E states. respectively. A simple electrostatic model was adapted t o predict dipole moments for CaCH3 and MECH(3). (C) 1996 American Inst itute of Physics.