Deperturbation analysis of the interacting C 2 π1/2 ( v=5), and D2σ+ ( v=1) levels of ScO

Perturbations have been observed between the C211i & SIM; D2E+ pair of interacting states of ScO molecule in the 28,0 0 0-30,060 cm-1 region using jet-cooled laser-induced fluorescence spectroscopy at 0.04 cm-1 resolution. The interactions among the D2E+, v = 1 and C211i, v = 5 states are manifested in irregularity in rotational constants, dispersed fluorescence spectra and relevant Franck-Condon overlaps. The perturbations among these states are understood in terms of homogeneous spin-orbit, spin-electronic and heterogeneous L-uncoupling interactions between the C211i & SIM; D2E+ states. The deperturbed molecular constants of the C211i, v = 5 and D2E+, v = 1 states have been determined by fitting the observed rovibronic transition wavenumbers to these excited states from the X2E+ ground state. The deperturbed position of the D2E+, v = 1 state lies only 1.5 cm-1 above the C 2 111/2 , v = 5 component and the states interact severely, being pushed apart by 18 cm-1 . In addition, the D2E+ state is observed in the v = 2 - 4 vibrational levels, which are found to be unperturbed. The deperturbed molecular constants of the vibrational levels of the C 2 11i , and D2E+ states found in the present and our earlier reported work are used to generate Rydberg-Klein-Rees (RKR) potential curves. Subsequently, the vibrational overlap (v11|vE), and radial integrals Bv11,vE, between the C211i and D2E+ states are computed and used to determine the pure electronic matrix elements connecting the electronic wavefunctions of these states.(c) 2022 Elsevier Ltd. All rights reserved.