Spectroscopic characterization of excited Ca(4s4d delta D-3(J))RG((3)Delta(1,2)) states (RG=Ar, Kr, Xe): No "heavy-atom" mixing of RG(nd delta) character into the wave functions

The excited Ca(4s4d delta D-3(J))RG[(3)Delta(1,2)] states (RG=Ar, Kr, Xe) h ave been characterized spectroscopically by R2PI (resonance-enhanced two-ph oton ionization) spectroscopy. The main vibrational progressions, assigned to Ca(4s4d delta D-3(1))RG[(3)Delta(1)]<--Ca(4s4p pi P-3(0)). RG[(3)Pi(0)-] transitions, have weak subbands 3.7+/-0.5 cm(-1) to the blue which have be en assigned to analogous transitions to the (3)Delta(2) upper states. For C aAr and CaKr, rotational analysis has confirmed this assignment. The (3)Del ta(2)/(3)Delta(1) splitting is within experimental error the value expected if the molecular spin-orbit coupling constant is derived entirely from the Ca(4s4d D-3(J)) atomic contribution. This indicates that there is no "heav y-atom" mixing of RG(nd delta) character into the wave functions of the CaR G((3)Delta) states. (C) 1999 American Institute of Physics. [S0021-9606(99) 01526-3].