High resolution analysis of transitions to the five lowest electronic states of samarium monoxide

Electronic structure of SmO and SmO− via slow photoelectron velocity-map imaging spectroscopy and spin-orbit CASPT2 calculations

“…As has been discussed by Paulovič et al, 19 a definitive assignment of the Ω value cannot be made for the lowestenergy CASPT2 states due to the very small energy separations between the states with respect to the resolution of the method. Fortuitously, the X(0 ) ground state of SmO identified by Linton and co-workers [11][12][13] is an Ω = 0 state; the lowest-energy SO-CASPT2 state reported here (Table I) is singly degenerate and therefore consistent with this assignment. Furthermore, the splitting between the lowest SO-CASPT2 states is in good agreement with experimental results, as will be discussed in detail below.…”

“…The literature is in agreement regarding the preferred septet spin state and 4f 5 6s 1 configuration of SmO. [11][12][13]15,[17][18][19]40 Higher-lying states involve excitations TABLE I. Theoretical SO-CASPT2 and experimental cryo-SEVI energies of low-lying states of neutral SmO from this work, compared to state assignments and experimental fluorescence measurements from the work of Linton and co-workers.…”

“…In much of the spectroscopic literature on SmO, [11][12][13]18 the electronic states are labeled with an (N)Ω convention, which represents the Nth state with a value of Ω for the projection of the total electronic angular momentum onto the internuclear axis. As has been discussed by Paulovič et al, 19 a definitive assignment of the Ω value cannot be made for the lowestenergy CASPT2 states due to the very small energy separations between the states with respect to the resolution of the method.…”

“…Linton and co-workers reported detailed energetics and state assignments for twelve low-lying states of SmO derived via high-resolution fluorescence measurements from excited states at term energies near 2 eV. [11][12][13] Willson and Andrews 14 reported infrared spectra of SmO 0/ in an argon matrix. Kafader et al 15 measured the anion photoelectron spectrum of SmO , reporting an electron affinity (EA) of 1.067(6) eV and a dense manifold of overlapping low-lying electronic states of SmO, as well as a continuum of higher-lying excited states spanning term energies of 1-2 eV.…”

A physics‐based model for the ionization of samarium by the MOSC chemical releases in the upper atmosphere

“…The visible luminescence spectrum of samarium oxide has been measured with reactions in the laboratory [Dickson and Zare, 1975] and with laser spectroscopic experiments [Hannigan, 1983;Linton et al, 1987;Bujin and Linton, 1989]. Electronic, vibrational, and rotational constants for energy levels of SmO are given in Table 3 [Linton et al, 1987;Bujin and Linton, 1989;Bujin and Linton, 1991]. Radiative transitions between each of the 11 higher-energy levels and the 15 lower energy levels produce a possible 165 emission wavelengths in the 540 to 800 nm range ( Figure 13a).…”