# tmQMg* Data Set: Excited State Properties of 74k Transition Metal Complexes

## TL;DR

The tmQMg* dataset provides excited state properties for 74,000 transition metal complexes to advance machine learning in photochemistry.

## Contribution

The novel contribution is the creation of a large dataset of excited state properties for transition metal complexes with solvatochromic effects.

## Key findings

- Excited state properties for 74k transition metal complexes were computed using TD-DFT.
- Solvatochromic effects in gas phase and acetone were quantified in terms of wavelength shifts and intensity changes.
- Natural transition orbitals were computed to determine charge transfer character of visible excitations.

## Abstract

The application of machine learning approaches to meaningful
problems
in chemistry and materials science is still challenged by the limited
availability of data. In order to close this gap, we report the tmQMg*
data set, which provides excited state properties for 74k mononuclear
transition metal complexes extracted from the Cambridge Structural
Database. All properties were computed at the TD-DFT ωB97xd/def2SVP
level of theory. The strongest electron excitations in the ultraviolet,
visible, and near-infrared ranges are included, together with the
wavelengths and intensities of the first 30 excited states. Further,
natural transition orbitals were computed for the strongest excitations
in the visible range to determine the nature of the associated charge
transfers. By computing the TD-DFT spectra in both gas phase and acetone,
we quantified solvatochromic effects, which are also provided with
the data set, in terms of both wavelength shifts and intensity changes.
The tmQMg* data set will enable the development of discriminative
and generative artificial intelligence models with respect to absorption
spectra, charge transfer character, and solvatochromism, enabling
novel advances in the field of transition metal photochemistry.