A combined ab initio and Franck‐Condon factor simulation study on the photodetachment spectrum of ScO₂⁻

Abstract

Restricted-spin coupled-cluster single-double plus perturbative triple excitation {RCCSD(T)} potential energy functions (PEFs) of the X(2)B2 state of ScO2 and the 1A1 state of ScO2(-) were computed, employing the augmented correlation-consistent polarized-weighted core-valence quadruple-zeta (aug-cc-pwCVQZ) basis set for Sc and augmented correlation-consistent polarized valence quadruple-zeta (aug-cc-pVQZ) basis set for O, and with the outer core Sc 3s(2)3p(6) electrons being explicitly correlated. Franck-Condon factors, which include allowance for Duschinsky rotation and anharmonicity, were calculated using the computed RCCSD(T) PEFs, and were used to simulate the first photodetachment band of ScO2(-). The simulated spectrum matches well with the corresponding experimental 355 nm photodetachment spectrum of Wu and Wang, J Phys Chem A 1998, 102, 9129, confirming the assignment of the photodetachment spectrum and the reliability of the RCCSD(T) PEFs used. Further calculations on low-lying electronic states of ScO2 gave adiabatic relative electronic energies (T(e)'s) of, and vertical excitation energies (T(v)'s) to, the 2A1, 2B1, and 2A2 states of ScO2 (from the X(2)B2 state of ScO2), as well as electron affinities (EAs) and vertical detachment energies (VDEs) to these neutral states from the 1A1 state of ScO2(-).

A combined ab initio and Franck–Condon factor simulation study on the photodetachment spectrum of HfO2−

“…It has been noted in ref. 18 and 19 that the computed bond angles of ScO 2 and YO 2 and their anions obtained by DFT calculations are significantly smaller than those obtained from high-level ab initio calculations. Consequently, it has been concluded that DFT methods are unreliable for the ground states of ScO 2 and YO 2 , and their anions.…”

“…20 In each case, it was found that, when correlation of the outer core (n À 1)s 2 (n À 1)p 6 electrons of the transition metal were adequately accounted for with a core-valence basis set, the RCCSD(T) method gave consistent and reliable results, and the simulated photodetachment spectrum of the transition metal dioxide anion matched very well the corresponding experimental spectrum (for details, see ref. [18][19][20]. In the present study, we have employed a similar computational strategy as used previously [18][19][20] to study low-lying electronic states of HfO 2 and the photodetachment spectrum of HfO 2 À .…”

“…[18][19][20]. In the present study, we have employed a similar computational strategy as used previously [18][19][20] to study low-lying electronic states of HfO 2 and the photodetachment spectrum of HfO 2 À . 6…”

Photoelectron spectra of early $3d$-transition metal dioxide cluster anions from $GW$ calculations

“…Photoelectron spectra of early 3d TMO − 2 clusters have been available up to photon energies of 5 − 6.5 eV since the pioneering studies of Wang and collaborators from more than two decades ago. [46][47][48][49][50][51][52] Their structural and electronic properties have been investigated [53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72] in various computational studies using methods based on DFT and quantum chemistry. While these TMO − 2 molecules are isostructural with little changes in the bond angles and lengths upon changing the TM element, their frontier molecular orbitals display a wide range of spatial localization properties and have significantly varying amounts of TM 3d and O 2p contents.…”

Simulated photodetachment spectra of AlH2−

“…This procedure has been used successfully to assign the photodetachment spectra of several triatomic negative ions. [14][15][16][17][18] However, as will be shown below, comparison between simulated and experimental spectra suggests that the experimental spectrum assigned to AlH 2 − in Ref. 1 is unlikely to be due to AlH 2…”