ON THE GROUND AND ELECTRONICALLY EXCITED-STATES OF NA3O - THEORY AND EXPERIMENT

Na3O has been generated by reacting preformed sodium clusters with O-2 and N2O in a crossed beam pickup arrangement. This ''superalkali'' sp ecies was probed by photodepletion spectroscopy coupled with one-photo n ionization mass spectroscopy to yield: (i) a first measure of visibl e/NIR region photodissociation cross sections showing several broad ab sorption features, (ii) a rough determination of the ground state diss ociation energy (1.48 +/- 0.04 eV), as well as (iii) a remeasurement o f the ionization potential (3.69 +/- 0.15 eV). The experimental invest igations were supplemented by quantum chemical ab initio calculations employing coupled-cluster methods for ground and excited states of Na3 O. Experiment and theory are in good agreement, allowing a tentative a ssignment of the Na3O depletion spectrum while providing further evide nce for the computed D-3h ground state. Observed and calculated dipole -allowed electronic transitions are discussed in terms of the unusual electronic structure of this nominally one excess-electron species. (C ) 1997 American Institute of Physics.