Physical interpretation of the X-ray restrained wave function

Objective

The aim of this project is the physical interpretation of the X-Ray restrained wave function (XRWF), obtained from a state-of the-art method of quantum crystallography, which allows one to derive model wave functions from a combination of the measured elastic X-ray scattering and quantum chemical calculations. Among various experimental wave function reconstruction techniques, XRWF approach provides the largest array of information on (potentially) any chemical system. However, no assessment of the meaning and physical plausibility of the resulting wave function has been proposed so far. Given the enormous impact of quantum information theory, this deficiency prevents an efficient use and development of the method. In fact, the electron correlation and relativity (among other phenomena) induce effects that one expects to retrieve with the XRWF approach, but at present the precise accuracy of their description by XRWF is unknown (only some features attributed to those causes have been investigated in details). The goal of this project is to develop a reliable methodology for the correct estimation of ability of XRWFs to include these effects and apply it to the current version XRWF method. In addition, this study will investigate how the lack of experimental accuracy and precision may affect the physical reliability of the resulting XRWFs. The results of this research are expected to significantly impact the rapidly growing field of quantum crystallography, providing tools to estimate the quality of the wave functions retrieved from experiments and to design appropriate corrections to improve the method. This project will be conducted at Politecnico di Milano under the supervision of one of the leading experts in the field of quantum crystallography Prof. Piero Macchi. It will help me develop and accelerate my academic career as a quantum crystallographer, bringing me key missing competences and increasing my recognition in the field.