title: The B 1Pi state of NaCs: high resolution laser induced fluorescence spectroscopy and potential construction.
abstract: The lowest (1)Pi state of the NaCs molecule, the B(1)(1)Pi state, was studied using a dye laser for inducing fluorescence that was resolved by a high resolution Fourier-transform spectrometer. The presence of argon buffer gas yielded rich rotational relaxation spectra allowing to enlarge the data set for the B(1)(1)Pi state, to obtain Lambda-splittings and to reveal numerous local perturbations. 543 weakly perturbed energy levels for rotational quantum numbers from J(')=5 to 168 and vibrational quantum numbers from v(')=0 to 25, which cover about 87% of the potential well depth, were used for a direct pointwise fit of the potential energy curve applying the inverted perturbation approach method. The resulting potential reproduces the term values for v(')=0-7 with an experimental accuracy of about 0.01-0.02 cm(-1), whereas for v(')=8-25 the deviations increase due to the perturbations, going to the order of 1 cm(-1); an extrapolation is made to the dissociation asymptote.
authors: Laser Center, Department of Physics, University of Latvia, Rainis Boulevard 19, LV 1586 Riga, Latvia.
authors: J
authors: J
authors: Zaharova
authors: O
authors: O
authors: Docenko
authors: M
authors: M
authors: Tamanis
authors: R
authors: R
authors: Ferber
authors: A
authors: A
authors: Pashov
authors: H
authors: H
authors: Knöckel
authors: E
authors: E
authors: Tiemann