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New Analysis Tools for Electronic Structure Computations: From Numbers to Chemical Insight
Felix Plasser (Loughborough)

Abstract:

Excited electronic states are central to many areas of modern science and computational methods are becoming ever more accurate in their description. However, a new bottleneck is encountered in the analysis of the computations owing not only to the quantity of data produced but also because many of the phenomena studied are difficult to grasp within the standard molecular orbital (MO) picture at all. To remove this barrier an extended wavefunction analysis framework has been developed over the last years. We will illustrate how these tools can be used to analyse excited state character in an automated and reproducible way [1] and how to bridge between the MO picture and other ways to view electronic structure: exciton theory, valence-bond theory and aromaticity.

We will first illustrate how excited-state localisation and charge transfer in interacting DNA bases can be quantified in an automated way and further processed to get a statistically meaningful description of the photophysics [2]. Subsequently, we will discuss the concept of excited-state aromaticity applying a newly developed method for the visualisation of chemical shielding tensors [3,4].

Figure 1: Graphical representation of aromaticity via a visualisation of the local chemical shielding tensors, reproduced from Ref. [3].

References

[1] F. Plasser, J. Chem. Phys. 2020, 152, 084108.

[2] J. J. Nogueira, F. Plasser, L. González, Chem. Sci. 2017, 8, 5682–5691.

[3] F. Plasser, F. Glöcklhofer submitted DOI: chemrxiv.13580885.

[4] F. Plasser, submitted, DOI: 10.26434/chemrxiv.14143730.