Energy and radiative properties of the low-lying NaRb states

Abstract

D 1 P ‐B 1 P transition dipole moments, as well as nonadiabatic L-uncoupling matrix elements between the examined 1 P and four lowest 1 S 1 states for both 23 Na 85 Rb and 23 Na 87 Rb isotopomers. The relevant MPPT ab initio matrix elements and energy curves were converted by means of the approximate sum rule to radiative lifetimes and L-doubling constants ( q factors! for the particular rovibronic levels of the B 1 P and D 1 P states. The theoretical lifetimes agree well with their experimental counterparts for both B 1 P and D 1 P states. The q factor estimates obtained in the singlet-singlet approximation are in good agreement with the experimental ones for the D 1 P(1<v8<12;7<J8<50) levels, exhibiting a pronounced difference for the B 1 P state. Considerably better agreement was achieved by accounting for the spin-orbit perturbation effect caused by the near-lying c 3 S 1 state. Relative intensity distributions in the D 1 P!X 1 S 1 dispersed fluorescence spectra excited by fixed Ar 1 laser lines were measured for v8(J8)50(44), 1(104), 4(25), 6(44,120), 10(36), and 12(50) D 1 P levels. The experimental intensities and term values were simultaneously embedded in the nonlinear least-square fitting procedure to refine theD 1 P potential.