Spectroscopic characterization of the weakly bound Ca(4s4d sigma D-3(3))center dot Ar[(3)Sigma(+)] state: Evidence for a substantial maximum in the potential curve at long range
Awk. Leung et al., Spectroscopic characterization of the weakly bound Ca(4s4d sigma D-3(3))center dot Ar[(3)Sigma(+)] state: Evidence for a substantial maximum in the potential curve at long range, J CHEM PHYS, 111(6), 1999, pp. 2484-2489
The weakly bound Ca(4s4d sigma D-3(3)). Ar[(3)Sigma(+)] state has been char
acterized by means of R2PI (Resonant Two-Photon Ionization) spectroscopy, u
sing transitions from the Ca(4s4p pi P-3(0)). Ar[(3)Pi(0)(-)] metastable st
ate prepared in a laser-vaporization/supersonic jet source. Because several
of the vibrational levels are above the dissociation limit [to Ca(4s4d D-3
(3))+Ar(S-1(0))], it is concluded that there must be a substantial maximum
in the Ca(4s4d sigma D-3(3)). Ar[(3)Sigma(+)] potential curve (> 200 cm(-1)
) at large R (> 4.0 Angstrom). This is discussed, and shown to be consisten
t with our earlier ideas of "penetration" of outerlobes of electron density
of metal atom excited states by RG (rare-gas) atoms. Perturbations observe
d, due to possible potential curve crossings with states of different elect
ronic symmetry, are also discussed. (C) 1999 American Institute of Physics.
[S0021-9606(99)00730-8].