Charge density distribution in La3Ni2O7 at high pressures

The recent discovery of pressure-induced superconductivity in La3Ni2O7 with a Tc close to 80K at pressures above 14GPa has generated considerable attention and calls for further investigation of the underlying mechanism. While the structure of the high-pressure phase that accommodates superconductivity could only be guessed from powder diffraction and theoretical calculations, a detailed single crystal diffraction study would provide the necessary structural details to prove the hypothesis that superconductivity is enabled by a strong mixing of nickel and oxygen orbitals. To address this aspect, we propose a detailed quantitative analysis of scattering intensities that allows not only to resolve structural uncertainties but also enables a direct visualisation of the electron density redistribution across the superconducting phase transition using multipolar refinement and refinement of experimental wave functions.