Extracting a wave function from experiment: a new approach based on the Coupled Cluster formalism*

Using experimental data to extract a given wave function is the goal pursued by the field of Quantum Crystalography [1]. Here, scattering data, with a focus on X-ray scattering, are used to constrain a wave function to reproduce experimental results. This approach has been successful to capture electron correlation [2], polarization, crystal field effects [3] and relativistic effects [4] and is currently being developed towards the treatment of larger biological systems [5]. In the present work, we choose a different direction by including spectroscopic data as additional or alternative experimental constraint. The Coupled Cluster and Equation of Motion formalism is used as the underlying theoretical model. Our aim is to develop a general framework from which an experimentally constrained wave function can be calculated.
We present the general formalism of our approach as well as preliminary results using simulated experimental data.

[1] Grabowsky et al., Chem. Sci., 8, 2017
[2] Alessandro Genoni et al., IUCrJ, 4 , 2017
[3] Alessandro Genoni, et al., Chem. A Eur. J., 24, 2018
[4] Lukáš Bučinskýet al., J. Phys. Chem.Lett, 120, 2016
[5] Lorraine Malaspina et al.,J. Phys. Chem. Lett., 10(22), 2019