# MARVEL analysis of the measured high-resolution rovibronic spectra of $^{48}$Ti$^{16}$O

## TL;DR

This paper presents a comprehensive set of high-precision rovibronic energy levels for ext{TiO} derived from critically reviewed experimental spectra using the MARVEL algorithm, significantly expanding and validating the spectroscopic data for this molecule.

## Contribution

It provides the first extensive, validated rovibronic energy level dataset for ext{TiO} based on high-resolution spectra, including many previously unassigned band-heads and transitions.

## Key findings

- Validated 48,590 transitions in ext{TiO} spectra.
- Determined 93 vibrational band origins, with 71 triplet and 22 singlet.
- Established rovibrational energy levels up to J=163.

## Abstract

Accurate, experimental rovibronic energy levels, with associated labels and uncertainties, are reported for 11 low-lying electronic states of the diatomic \TiO\ molecule, determined using the \Marvel\ (Measured Active Rotational-Vibrational Energy Levels) algorithm. All levels are based on lines corresponding to critically reviewed and validated high-resolution experimental spectra taken from 24 literature sources. The transition data are in the 2 $-$ 22,160 \cm{} region. Out of the 49,679 measured transitions, 43,885 are triplet-triplet, 5710 are singlet-singlet and 84 are triplet-singlet transitions. A careful analysis of the resulting experimental spectroscopic network (SN) allows 48,590 transitions to be validated. The transitions determine 93 vibrational band origins of \TiO\, including 71 triplet and 22 singlet ones. There are 276 (73) triplet-triplet (singlet-singlet) band-heads derived from \Marvel\ experimental energies, 123 (38) of which have never been assigned in low or high resolution experiments. The highest $J$ value, where $J$ stands for the total angular momentum, for which an energy level is validated is 163. The number of experimentally-derived triplet and singlet \TiO\ rovibrational energy levels is 8682 and 1882, respectively. The lists of validated lines and levels for \TiO\ are deposited in the Supporting Information to this paper.