OODR SPECTROSCOPY OF NA-3 AND ROTATIONAL ANALYSIS OF A VIBRATIONALLY EXCITED-LEVEL IN THE (A)OVER-TILDE STATE

Using optical-optical double resonance techniques the rotational assig nment of the (A) over bar (2)A(2)-(X) over bar B-2(2) system of Na-3 c ould be extended to transitions involving vibrationally excited levels in the (A) over bar state. About 30 measured transition frequencies w ere fitted, using the Hamiltonian of an asymmetric rotor and including spin-rotation interaction. The averaged geometry of the sodium trimer in the vibrationally excited (A) over bar state was derived from the rotational constants. Vibrational classification of the observed (A) o ver bar-(X) over bar bands from a Jahn-Teller analysis by Dugourd et a l. (J. Chem. Phys. 93, 2322, 1990) is discussed. (C) 1995 Academic Pre ss, Inc.