Laser absorption spectroscopy of LaF: Analysis of the B-1 Pi-X(1)Sigma(+) transition

Laser absorption spectra for the LaF[16.6]0(+)-X(1) Sigma(+) (0,0), B-1 Pi-X(1) Sigma(+) (3,0), (2,0), (1,0), (2,1), and (3,2) bands were recorded. Accurate molecular constants and the internuclear distance for the X(1) Sigma(+) state are presented, Rotational perturbations were evident in the B-1 Pi (upsilon = 1, 2, 3) levels, These perturbations were analyzed and assigned to interactions with the c(1)(3) Delta(1) and [16.6]0(+) states. Equilibrium molecular constants for the B-1 Pi, [16.6]0(+) and c(1)(3) Delta(1) states are reported. (C) 1997 Academic Press.