The Spectrum of ThO: Rotational Analysis of the L1Π-X1Σ+ and N1Π-X1Σ+ Systems

Two new systems of ThO have been rotationally analysed. The systems are assigned L 1?-X 1?+ and N 1?-X 1?+. They are located at about 4020 ? and 3605 ?. In both systems the 0-0 and 1-1 bands have been studied. Molecular constants are given. All upper levels are somewhat perturbed.