A theoretical investigation of the $${{\rm SO}}({{B}^{3}\Sigma ^{-}{-}{X}^{3}\Sigma ^{-}}$$) vibronic transition using accurate analytical potential energy functions

Ultraviolet photoabsorption in the $B\,{}^3Σ^- - X\,{}^3Σ^-$ and $C\,{}^3Π - X\,{}^3Σ^-$ band systems of SO sulphur isotopologues

“…The present B − X electronic transition moment for SO lies between the values determined experimentally for the analogous transitions in the isovalent molecules O 2 [62] and S 2 [40,63], ∼ 0.87 and 0.97 ± 0.05, respectively. On the other hand, B−X electronic transition moments for SO calculated ab initio [35][36][37] are significantly smaller than our experimental value in the region of internuclear distance probed by absorption from X(v = 0). The cause of this difference is not clear.…”

“…The estimated total uncertainty encompasses agreement with a previously measured 32 S 16 O cross section [25] and B 3 Σ − (v = 0 − 2) lifetimes [21], but somewhat disagrees with a further set of B 3 Σ − (v = 0 − 3) lifetimes [24]. However, the new B 3 Σ − − X 3 Σ − transition moment is in significant disagreement with previous ab initio calculations [35,37] that suggest a 50% smaller cross section, while C 3 Π − X 3 Σ − transition moments are found to agree well.…”

“…This interaction results in the peculiar shape of the B 3 Σ − potential-energy curve and a sharp alteration of its electronic-configuration near 2.25 Å, as evidenced by an exchange of electronic transition moment between the diabatic B 3 Σ − − X 3 Σ − and higher-energy 3 Σ − − X 3 Σ − transitions. Further ab initio calculations of excited SO states have been recently performed by Feng and Zhu [36], who also computed many spin-orbit interaction energies, and da Silva and Ballester [37]. Previous experimental studies [18,19] concerning the photodissociation spectrum of SO isotopologues appear to be limited to 32 S 18 O with theoretical results extended to all S substitutions [35].…”

A comparative review of 50 analytical representation of potential energy interaction for diatomic systems: 100 years of history

“…The EHFACE2U potential energy curve is considered one of the best and more accurate functions to describe diatomic interactions, it is still widely used in recent researches [168–170]. In a recent work presented by da Silva and Ballester [171] the diatomic potential energy curves for triplet electronic states, X 3 ∑ − and B 3 ∑ − of SO has been described using the approach proposed by Varandas and da Silva [167]. Another recent application this potential can be seen in da Silva et al [172].…”