Influence of modelling disorder on Hirshfeld atom refinement results of an organo-gold(I) compound

Abstract

Details of the validation of disorder modelling with Hirshfeld atom refinement (HAR) for a previously investigated organo-gold(I) compound are presented here. The impact of refining disorder on HAR results is discussed using an analysis of the differences of dynamic structure factors. These dynamic structure factor differences are calculated from thermally smeared quantum mechanical electron densities based on wavefunctions that include or exclude electron correlation and relativistic effects. When disorder is modelled, the electron densities stem from a weighted superposition of two (or more) different conformers. Here this is shown to impact the relative importance of electron correlation and relativistic effect estimates expressed by the structure factor magnitudes. The role of disorder modelling is also compared with the effect of the treatment of hydrogen anisotropic displacement parameter (ADP) values and atomic anharmonicity of the gold atom. The analysis of ADP values of gold and disordered carbon atoms showed that the effect of disorder significantly altered carbon ADP values and did not influence those of the gold atom.

Crystal Engineering of Hydrogen Bonding for Direct Air Capture of CO2: A Quantum Crystallography Perspective

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Hydrogen atoms in supramolecular chemistry: a structural perspective. Where are they, and why does it matter?

“…Supramolecular chemistry poses some specific challenges to these approaches, in particular the size and complexity of their structures, data quality issues, as well as the presence of heavy elements and disorder. However, since the first report of diffraction data treated with this technique, 118 Hirshfeld Atom Refinement has become increasingly popular 119–121 and more easily accessible 122 with improvements in IT, molecular modelling and DFT (in particular) in recent years. As such, it is inevitable that these integrated calculation methods will become increasingly relevant in the years to come.…”

Refinement of X-ray and electron diffraction crystal structures using analytical Fourier transforms of Slater-type atomic wavefunctions in Olex2

“…In particular, elements with Z > 35 exhibit large residual electron-density values after refinement using both spherical and non-spherical electrondensity models. Examples exhibiting the structured appearance of these residual electron-density distributions, even after non-spherical refinements, were presented in recent studies for Hg, Os or Au (Malaspina et al, 2019;Pawle ˛dzio et al, 2021Pawle ˛dzio et al, , 2022. The increasing threshold for residual electron-density values of structures containing heavier elements before a warning is triggered during data validation procedures by the IUCr CheckCIF procedure (https://checkcif.iucr.org/) tries to address these growing discrepancies during structure validation.…”